Electronic verification machine for documents

ABSTRACT

Determination of the authenticity and integrity of various types of documents such as lottery tickets is accomplished by using an electronic verification machine to compare data contained in electronic circuits printed on the document to document data printed on the document. The electronic circuits are printed on the document in conductive or semiconductive ink using, for example, the gravure printing process, and the presence and status of the circuits can be used to verify or authenticate the document. Data can be represented in the electronic circuits by the electrical signature of the circuit which is measured by the electronic verification machine. In the case of lottery tickets, a ticket can be validated by having the electronic verification machine determine which play spots have been removed from the ticket and comparing data on the ticket with the removed play spots to determine a play redemption value for the ticket. Document verification or lottery ticket validation can also be accomplished by transmitting signature data from the electronic circuits via the electronic verification machine to a central computer for comparison with document data.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application divisional of U.S. Ser. No. 09/165,666, filed Oct. 3,1998 now U.S. Pat. No. 6,053,405, which was a continuation-in-part ofU.S. Ser. No. 08/837,304 filed Apr. 11, 1997 U.S. Pat. No. 5,818,019issued Oct. 6, 1998, which was a continuation of Ser. No. 08/486,588filed Jun. 7, 1995 now U.S. Pat. No. 5,621,200, issued Apr. 15, 1997,which was a continuation-in-part of Ser. No. 08/263,890 filed Jun. 22,1994 now U.S. Pat. No. 5,471,039, issued Nov. 28, 1995.

FIELD OF THE INVENTION

The invention relates to an electronic apparatus for obtaininginformation from a document, and more particularly, to an apparatus fordetermining the location and shape of a conductive area printed on adocument such as a lottery ticket.

BACKGROUND OF THE INVENTION

It is often desirable to obtain information from documents in additionto the human readable information printed on the surface of thedocument. For instance, documents of many types are susceptible totampering, alteration and counterfeiting. Lottery tickets forprobability games are an example of a document which is particularlysusceptible to tampering. A probability game lottery ticket normally hasplay areas, each containing play indicia covered by an opaque material,for example a latex material. To play the game, an individual scratchesoff the latex covering a specified number of the play areas to revealthe play indicia underneath. The player then determines if thecombination of revealed play indicia is a winner such as the playindicia are all the same symbol or add up to a winning number.

Part of the popularity of such probability games is derived from thefact that each and every ticket is a potential winner. If a player haslost, the player can scratch off the latex covering the remaining playareas and verify that at least one winning combination is present.Consequently, this type of game is generally perceived by lotteryplayers as being more legitimate than other types of instant lotterygames.

The fact that every ticket is potentially a winner also invites playersto tamper with the tickets. Because every ticket can win if the rightplay areas are selected, some players look for ways to determine theplay indicia contained in every play area in order to identify thelocation of a winning combination. If the player can conceal the factthat he has seen the play indicia, the player subsequently can removethe latex covering from the play areas containing the winningcombination and claim a prize.

One technique used to accomplish this result involves lifting the latexto look at the play indicia before gluing the latex back into place.Typically, probability game lottery tickets are validated by the visualobservation of a human lottery agent. It can be difficult to visuallydetect this sort of tampering. Thus, probability game lottery ticketsare particularly susceptible to fraudulent tampering and because noeffective way of preventing or detecting such tampering has beendeveloped, probability lottery games have not become commerciallysuccessful.

A second threat to the integrity of a document is the intentionalalteration of its contents. For example, an individual may try to alterthe information on a driver's license, contract, test answer form,invoice or inventory form. Such an alteration may involve the changingof a number in the document by removing the original number andinserting a new number. In the case of laminated documents, such asdrivers licenses, the document can be delaminated and the driver'sphotograph can be replaced with the photograph of another person and thelicense relaminated. Such alterations can be very difficult to detect,especially if there are no other copies of the document.

A third type of problem posed in the document security context involvescounterfeiting. Rather than altering an existing document, thecounterfeiter actually creates a document and attempts to pass it off asbeing genuine. Thus, paper currency, tickets, tags, and labels are oftencounterfeited and proffered as the real thing. The magnitude of thisproblem has substantially increased with the advent of the color photocopier.

For example, the owner of a trademark might sell t-shirts bearing thattrademark to increase the value of the shirt. In an attempt to thwartpirates, the trademark owner might also attach a identifying tag to thet-shirts. This makes it easier to determine whether a given t-shirt isgenuine. In order to disguise the fact that t-shirts are counterfeits, acounterfeiter will reproduce not only the t-shirt's design, but also thetag. While being forced to create a similar looking tag will increasehis costs, if the value of the trademark is sufficiently high, thecounterfeiter will continue to attach a counterfeited tag.

There have been a number of techniques developed to improve the securityof printed documents including the addition of magnetic materials to thedocument which are magnetically encoded with information that can beused to verify its authenticity. However, magnetically encodedinformation can in many instances be easily detected, read and alteredand thus is not always suitable for verifying the integrity of adocument and as such is generally not suitable for lottery tickets andprobability tickets in particular. Another disadvantage of magneticallyencoding information on a document, is that alterations to themagnetically encoded information are not generally detectable. Othermethods for verifying the integrity of lottery tickets have been usedsuch as inks that change color when tampered with but none of thesemethods have been sufficiently secure to permit the commercial sale ofprobability tickets.

There have also been a number of techniques developed for usingelectrical circuits in documents to represent information. See forexample U.S. Pat. Nos. 3,699,311, 5,471,040 and 5,484,292. However,these documents suffer from a number of disadvantages including beingexpensive to manufacture and the delectability of the circuits in thedocument.

Hence, it is desirable to provide an improved system for obtaininginformation from documents to discourage tampering, alteration andcounterfeiting.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a system forobtaining information from a document utilizing an electronic apparatusfor determining the characteristics of an electronic circuit elementprinted on the document.

Another object of the invention is to provide a system for obtaininginformation from documents utilizing an electronic verification machinefrom receiving the documents and electronically coupling with a circuitelement printed on the document such that a characteristic of thecircuit element can be detected.

A further object of the invention is to provide an electronicverification machine for use with a document having a printed circuitelement where the electronic verification machine electronically coupleswith the circuit element and generates a detection signal representing acharacteristic of the circuit element. The electronic verificationmachine applies an excitation signal to the circuit element printed onthe document and includes a detection circuit which generates thedetection signal in response to the excitation signal. The excitationsignal can be an AC signal having a predetermined frequency which can becoupled to the circuit element by a number of different methodsincluding direct physical contact, capacitive or inductive coupling.

Still another object of the invention is to provide an electronicverification machine for use with a document having at least oneconductive material printed on the surface where the verificationmachine includes an array of sensor plates, a circuit for applying an ACexcitation signal to the document and a detection circuit connected tothe sensor plates for detecting the presence of at least a portion ofthe conductive material. The detection circuit can also be used togenerate a signal representing the shape of the conductive material onthe document which in turn can be used to compare the shape to apredetermined shape stored in a memory.

Yet another object of the invention is to provide an electronicverification machine for use with lottery tickets having a scratch offcoating that includes a conductive material where the electronicverification machine includes an excitation circuit for applying anexcitation signal to the ticket and a validation circuit responsive tothe excitation signal for determining the location of the scratch-offcoating on the ticket.

A further object of the invention is to provide an electronicverification machine for use with pull-tab tickets where the upperportion of the ticket having the pull tabs also includes a layer ofconductive ink such that the verification machine by applying a signalto the ticket can determine if one or more of the pull tabs have beenremoved. The excitation signal can also be used to determine if theticket is a legitimate ticket.

An additional object of the invention is to provide an electronicverification machine that can determine the electrical signature of acircuit element printed on a document and apply a signal to the circuitelement sufficient to stigmatize the document. This stigmatization canbe achieved if for example the circuit element is a fuse and the appliedsignal has sufficient power to blow this fuse. In addition tostigmatization, this technique can be used to store data on the documentwhere a selected number of circuit elements or fuses are blown by theapplied signal.

These objects are accomplished in the present invention by printing anelectrical circuit onto the document. The circuits are printed inconductive or semiconductive ink using, for example, a gravure printingprocess. When the authenticity of the document is determined, anelectronic verification machine is used to detect the presence andstatus of the circuit. Any attempted tampering or alteration of theprinted document causes detectable changes in the characteristics of thecircuit. Additionally, counterfeiting documents is made more difficultbecause a circuit acceptable to the electronic verification machine alsomust be counterfeited. The expense of determining how to print, andactually printing, an acceptable circuit generally outweighs anypossible gain from the counterfeiting of documents. Therefore, thesystem reduces or eliminates counterfeiting of printed documents.

The secure document system is potentially useful for a wide variety ofdocuments including, but not limited to, lottery tickets, especiallyprobability game lottery tickets, currency, traveller's checks, creditcards, money cards, passports, stock and bond certificates, bank notes,driver's licenses, wills, coupons, rebates, contracts, food stamps,magnetic stripes, test answer forms, invoices, inventory forms, tags,labels and original art work.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan drawing of a probability lottery ticket having anelectrical signature according to the invention;

FIG. 2 is a plan drawing of the partial electrical circuit that providesthe card in FIG. 1 its electrical signature;

FIG. 3 is a schematic representation of a gravure printing press used toprint the ticket in FIG. 1;

FIG. 4 is a plan drawing of the first layer printed on the ticket inFIG. 1;

FIG. 5 is a plan drawing of the second layer printed on the ticket inFIG. 1;

FIG. 6 is a plan drawing of the third layer printed on the ticket inFIG. 1;

FIG. 7 is a plan drawing of customized graphics printed on the firstportion of the ticket in FIG. 1;

FIG. 8 is a plan drawing showing the placement of the play indicia,validation number, inventory control number, and bar code which areprinted on the ticket in FIG. 1;

FIG. 9 is a plan drawing of the back of the ticket in FIG. 1;

FIG. 10 is a plan drawing of the fourth layer printed on the ticket inFIG. 1;

FIG. 11 is a plan drawing of the fifth and sixth layers printed on theticket in FIG. 1;

FIG. 12 is a plan drawing of the seventh layer printed on the lotteryticket on FIG. 1;

FIG. 13 is a plan drawing of the eighth layer printed on the lotteryticket in FIG. 1;

FIG. 14 is a perspective view of an electronic verification machineaccording to the invention;

FIG. 15 is a perspective view of an alternative embodiment of anelectronic verification machine according to the invention;

FIG. 16 is a plan drawing of the user interface of the electronicverification machine in FIG. 14;

FIG. 17 is a block diagram of the major internal components of theelectronic verification machine in FIG. 14;

FIG. 18 is a block diagram of the circuitry of the electronicverification machine in FIG. 14;

FIG. 19 is a plan drawing of the partial printed circuit used todetermine the authenticity and integrity of the bar code of the ticketin FIG. 1;

FIG. 20 is a plan drawing of the partial printed circuit used todetermine the authenticity and integrity of the play spot areas of theticket in FIG. 1;

FIG. 21 is a plan drawing of another printed partial circuit which canbe used to determine the authenticity and integrity of a probabilitylottery ticket;

FIG. 22 is a schematic circuit diagram of the completed circuit which isformed when the partial circuit in FIG. 20 is coupled to an electronicverification machine;

FIG. 23 is a plan drawing of a probability lottery ticket before theticket is printed with yet another partial circuit which be used todetermine the authenticity and integrity of the ticket;

FIG. 24 is a plan drawing of the release coat printed on the ticket inFIG. 23;

FIG. 25 is a plan drawing of the partial circuit used to determine theauthenticity and integrity of the ticket in FIG. 23;

FIG. 26 is a plan drawing of the ticket in FIG. 23 in its final printedformat;

FIG. 27 is a plan drawing of a second embodiment of the release coatprinted on the ticket in FIG. 23;

FIG. 28 is a plan drawing of the circuit used to determine theauthenticity and integrity of the ticket in FIG. 23;

FIG. 29 is a plan drawing of another circuit which can be used todetermine the authenticity and integrity of a probability game ticket;

FIG. 30 is a plan drawing of another circuit which can be used todetermine the authenticity and integrity of a probability game ticket;

FIG. 31 is a plan drawing of four printed resistors having differentresistances;

FIG. 32 is a plan drawing of a partial printed circuit which includes acalibration line;

FIG. 33 is a partial plan drawing illustrating a ticket inductivelycoupled to an electronic verification machine;

FIG. 34 is a partial plan drawing of a conductor which can be printed ona ticket to provide an RF antenna;

FIG. 35 is a partial schematic circuit diagram of circuit which measuresthermal variations to determine the authenticity and integrity of aticket;

FIG. 36 is a plan drawing of a lottery ticket having sixteen play spotareas;

FIG. 37 is a plan drawing of the ticket in FIG. 36 having the play spotareas removed to reveal the underlying play indicia;

FIG. 38 is a block diagram of a second embodiment of an electronicverification machine;

FIG. 39 is a partial sectioned side view of the electronic verificationmachine of FIG. 38 illustrating a document transport mechanism;

FIG. 40 is a block diagram of a portion of the circuitry of theelectronic verification machine of FIG. 38;

FIG. 41 is a schematic diagram of a position sensor array and buffercircuit that can be used with the circuit of FIG. 39;

FIG. 42 is a perspective view of an alternative position sensor arraythat can be used with the electronic verification machine of FIG. 38;

FIG. 43 is a plan view of a first lottery ticket suitable for use withthe electronic verification machine of FIG. 38;

FIG. 44 is a game signature map representing the location of ascratch-off coating having conductive material on the lottery ticket ofFIG. 43;

FIG. 45 is a data map representing the data out put of the electronicverification machine of FIG. 38 for the lottery ticket of FIG. 43;

FIG. 46 is an exploded perspective view of a pull-tab lottery ticket;

FIG. 47 is an illustrative top view of the pull-tab lottery ticket ofFIG. 46 in conjunction with a signature map;

FIG. 48 is an illustrative top view of the pull-tab lottery ticket ofFIG. 46 positioned below an electronic verification machine sensorarray;

FIG. 49 is a plan drawing of a second embodiment of a probability ticketaccording to the invention;

FIG. 50 is a plan drawing of the circuit elements that form parts of theticket shown in FIG. 49;

FIG. 51 is a schematic representation of a gravure printing press usedto print the ticket in FIG. 49;

FIG. 52 is a plan drawing of a first blocking layer that is part of theticket in FIG. 49;

FIG. 53 is a plan drawing of an alternative embodiment of the firstblocking layer shown in FIG. 53;

FIG. 54 is a plan drawing of a second alternative embodiment of thefirst blocking layer shown in FIG. 53;

FIG. 55 is a plan drawing of one of the circuit elements in FIG. 49 asprinted on the first blocking layer in FIG. 52;

FIG. 56 is a plan drawing of one of the circuit elements in FIG. 49 asprinted on the first blocking layer in FIG. 53;

FIG. 57 is a plan drawing of one of the circuit elements in FIG. 49 asprinted on the first blocking layer in FIG. 54;

FIG. 58 is a plan drawing of a masking layer that is apart of the ticketshown in FIG. 49;

FIG. 59 is a plan drawing of a primer layer that is apart of the ticketshown in FIG. 49;

FIG. 60 is a plan drawing of the display portion graphics that are partof the ticket shown in FIG. 49;

FIG. 61 is a plan drawing of play indicia which are part of the ticketshown in FIG. 49;

FIG. 62 is a plan drawing of the back of the ticket shown in FIG. 49;

FIG. 63 is a plan drawing of a seal coat which is part of the ticketshown in FIG. 49;

FIG. 64 is a plan drawing of a release coat which is part of the ticketshown in FIG. 49;

FIG. 65 is a plan drawing of an upper blocking layer that is part of theticket shown in FIG. 49;

FIG. 66 is a plan drawing of an alternative embodiment of the upperblocking layer in FIG. 65;

FIG. 67 is a plan drawing a second alternative embodiment of the upperblocking layer in FIG. 65;

FIG. 68 is a plan drawing of some of the circuit elements shown in FIG.50 as printed on the blocking layer shown in FIG. 65;

FIG. 69 is a plan drawing of some of the circuit elements shown in FIG.50 as printed on the blocking layer shown in FIG. 66;

FIG. 70 is a plan drawing of some of the circuit elements shown in FIG.50 as printed on the blocking layer shown in FIG. 67;

FIG. 71 is a plan drawing is a plan drawing of a scratch-off layer thatis part of the ticket shown in FIG. 49;

FIG. 72 is a plan drawing of a combined seal-release coat that can beused on the ticket instead of the seal coat and the release coat thatare shown in FIGS. 63 and 64, respectively;

FIG. 73 is an enlarged plan drawing of one of the circuit elements shownin FIG. 50 and illustrates a first printing defect;

FIG. 74 is a plan drawing of the circuit element in FIG. 72 andillustrates a second printing defect;

FIG. 75 is an enlarged plan drawing of one of the circuit elements inFIG. 50 and shows the configuration of the circuit element relative to aplay indicia and a release coat portion or a seal-release coat portion;

FIG. 76 is a plan drawing of an alternative embodiment of the circuitelement shown in FIG. 75;

FIG. 77 is a plan drawing of a marker card according to the invention;

FIG. 78 is a plan drawing of the circuit elements which are part of themarker card shown in FIG. 77;

FIG. 79 is a plan drawing is a plan drawing of the play indicia whichare part of the marker card in FIG. 77;

FIG. 80 is a plan drawing of a seal coat which is part of the markercard in FIG. 77;

FIG. 81 is a plan drawing of a release coat that is part of the markercard in FIG. 77;

FIG. 82 is a plan drawing of an alternative embodiment of the releasecoat shown in FIG. 81;

FIG. 83 is a plan drawing seal-release coat that can be used instead ofthe seal coat and the release coat that are shown in FIGS. 80 and 81,respectively;

FIG. 84 is a plan drawing of an alternative embodiment of theseal-release coat in FIG. 83;

FIG. 85 is a plan drawing of the circuit elements in FIG. 78 as printedon the release coat shown in FIG. 81;

FIG. 86 is a plan drawing of the circuit elements in FIG. 78 as printedon the release coat shown in FIG. 82;

FIG. 87 is a plan drawing of the circuit elements in FIG. 78 as printedon the seal-release coat shown in FIG. 83;

FIG. 88 is a plan drawing of the circuit elements in FIG. 78 as printedon the seal-release coat shown in FIG. 84;

FIG. 89 is a plan drawing of a scratch-off layer that is part of theticket shown in FIG. 77;

FIG. 90 is a plan drawing of a data card according to the invention;

FIG. 91 is a plan drawing of an alternative embodiment of the data cardin FIG. 91;

FIG. 92 is a plan drawing a laminated document according to theinvention;

FIG. 93 is a plan drawing of a lower laminate and a lower circuitelement that is part of the laminated document in FIG. 92;

FIG. 94 is a plan drawing of an upper laminate and an upper circuitelement that is part of the laminated document in FIG. 92;

FIG. 95 is a plan drawing of an information document that is part of thelaminated document shown in FIG. 92;

FIG. 96 is a perspective view of a third electronic verification machineaccording to the invention;

FIG. 97 is a side perspective view of the electronic verificationmachine in FIG. 96 with the cover removed;

FIG. 98 is a partially cut-away exploded side perspective view of theelectronic verification machine in FIG. 96;

FIG. 99 is a block diagram of the relationship among the majorcomponents of the electronic verification machine in FIG. 96;

FIG. 100 is a top plan view of a sensor head which forms a part of theelectronic verification machine in FIG. 96;

FIG. 101 is a simplified partial circuit diagram of the capacitivecoupling between the sensor head in FIG. 100 and a document beingtested;

FIG. 102A is a plan view of a first printed layer pattern that can beused with the electronic verification machine in FIG. 96;

FIG. 102B is a conceptual representation of two capacitors which areformed when the sensor array of the electronic verification machine inFIG. 96 is capacitively coupled to a document which contains the firstprinted layer pattern shown in FIG. 102A;

FIG. 103A is a plan view of a second printed layer pattern that can beused with the electronic verification machine in FIG. 96;

FIG. 103B is a conceptual representation of two capacitors which areformed when the sensor array of the electronic verification machine inFIG. 96 is capacitively coupled to a document which contains the secondprinted layer pattern shown in FIG. 103A;

FIG. 104A is a plan view of a third printed layer pattern that can beused with the electronic verification machine in FIG. 96;

FIG. 104B is a conceptual representation of two capacitors which areformed when the sensor array of the electronic verification machine inFIG. 96 is capacitively coupled to a document which contains the thirdprinted layer pattern shown in FIG. 104A;

FIG. 105 is a example of a printed circuit element that can beelectronically altered by the electronic verification machine in FIG.96, to stigmatize a document being tested;

FIG. 106 is a functional block diagram of a stigmatization circuit thatcan be used to stigmatize a document having the printed circuit elementof the type shown FIG. 105; and

FIG. 107 is a conceptual diagram which illustrates the use of theelectronic verification machine in FIG. 96 to measure the thickness of adocument being tested.

DETAILED DESCRIPTION OF THE INVENTION

I. General Overview

The present invention is directed to a method and to an interrelatedgroup of devices for determining the authenticity and integrity of adocument and includes printing a portion of an electrical circuit on thedocument or applying a material having electrical conductive propertieson the document. “Document”, as that term is used herein, is not limitedto conventional printed papers but includes any type of flexiblesubstrate as well as rigid substrates such as printed circuit boards. Adocument is authentic if it is not the product of counterfeiting. Theintegrity of a document relates to its current physical state ascompared to its initial physical state and is affected by unauthorizedmodifications or attempted modifications of the document by, forexample, subjecting the document to chemicals, heat, light, or pressure.The electrical characteristics of the printed circuit or the location ofthe conductive material provide the basis for determining both theauthenticity and the integrity of the document. These characteristicscan also be used to obtain data from the document.

A first method is to choose a predetermined, measurable electricalproperty, for example, a known resistance or capacitance, that willserve as the electrical signature of the document. Next, at least aportion of an electrical circuit is printed on the document usingconductive or semi-conductive inks. The electrical circuit is designedso that when the circuit is completed, the circuit will generate anelectrical signature that is substantially equal to a chosenpredetermined electrical signature. Last, the circuit on the document iscoupled to an electronic verification machine for determining theauthenticity and integrity of the document by comparing the signalcharacteristics of the circuit on the document to the predeterminedsignature.

The electronic verification machine provides at least three functions.First, the electronic verification machine completes the circuit andprovides a power source for exciting the circuit. Second, the electronicverification machine measures the resulting electrical signature of thedocument. And third, the electronic verification machine determineswhether the measured electrical signature is substantially the same asthe predetermined electrical signature. There are a number of ways inwhich the electronic verification machine can determine the authenticityand integrity of the document. The electronic verification machine candirectly determine the authenticity and integrity of the document byusing data directly available to the electronic verification machine.Alternatively, the electronic verification machine can indirectlydetermine the authenticity and integrity of a document by communicatingthe measured electrical signature to a remote computer which containsdata related to the predetermined electrical signature for the document.

Determining the authenticity and integrity of the document is, in itssimplest form, a logical progression. Generally, if an electricalsignature can not be measured, the document is not authentic, is not inits original integral state, or both. On the other hand, if anelectrical signature can be measured and the measured electricalsignature is substantially the same as the predetermined electricalsignature, the document can be assumed to be authentic and in itsoriginal integral state. If an electrical signature can be measured butis substantially different than the predetermined electrical signature,at the very least the document is not in its original integral state.This method will be explained in terms of a representative documentwhich in this case is a probability game lottery ticket.

A second method is similar to the first method but involves thedetermination of the location of conductive materials on the document.This method will be explained in conjunction with the second embodimentof the electronic verification machine.

II. Probability Game Lottery Ticket Configuration

The preferred embodiment of the invention is an electronic verificationmachine that can be used to determine the integrity and authenticity ofa document, such as a probability game lottery ticket. Consequently, abrief overview of probability game lottery tickets is helpful. Aprobability game lottery ticket typically includes a group of play areasor play spots, each containing play indicia covered by an opaquematerial, usually a latex material. A player can win a prize if heremoves the latex from a predetermined combination or combinations ofplay spots which define one or more winning redemption values. Generallythe player is instructed to rub off only a specified number of playspots. Thus, a game may require a player to rub off three play spots. Inthis case, if the player rubs off more than three play spots, the ticketis void and player automatically loses. If the play indicia under theremoved play spots match one of the predetermined combination(s), theplayer is eligible to redeem the ticket for a prize. On the other handif the removed play spots do not match one of the predeterminedcombination(s), the redemption value of the ticket will be zero.

FIG. 1 illustrates the final printed format of a probability game ticket50 according to one embodiment of the invention. The ticket 50 includesa card substrate 52 which is generally divided into two portions. Afirst portion 54, the display portion, contains various types of printedinformation such as the name 56 of the probability game, information 58related to the rules for playing the ticket, and customized art work 60.A second portion, the playing field portion 62, includes overprint areas66, 68 and 76. The square overprint areas 66 define a group of play spotareas 72A-H of the ticket 50. As shown in FIG. 1, the overprint area ofone play spot area 72A has been rubbed off the reveal the underlyingplay indicia 74. The play indicia 74 can take any on a variety of formsincluding, as shown here, a dollar value. The play indicia 74 can alsobe formed from letters or words alone, numbers alone, or symbols alone,or any combination of letters, numbers, or symbols. Although notillustrated, it is to be understood that play indicia similar to playindicia 74 underlie each of the play spot areas 72B-H.

The overprint area 76 defines the void-if-removed area of the ticket 50.A validation number 78, shown in FIG. 8, underlies the void-if-removedarea defined by the overprint area 76. The validation number 78 containsvarious types of security information including a portion that isusually algorithmically related to the pack number and ticket number fora particular ticket, such as the ticket 50. The pack number identifiesthe pack from which the ticket 50 originates. The ticket number relatesto the position of the ticket 50 within the pack. In addition as will beexplained below, the validation number 78 can also include informationrelated to the electrical signature(s) of the ticket 50. The validationnumber 78 is useful for determining the authenticity and integrity ofthe ticket 50, as explained in greater detail below, in Section V.

A bar code 80 is also printed within the playing field portion 62 of theticket 50. The bar code 80 can include information related to thevalidation number, the pack and ticket numbers for the ticket 50 and tothe redemption values of various combinations of the play indicia 74 ineach of the play spot areas 72A-H. The bar code 80 can also be used tostore information about the value of the play indicia 74 on the ticket50, as is explained in greater detail below, in Section V.

FIG. 2. illustrates a partial electrical circuit 81 which is interposedbetween the overprint areas 64-68 and the play indicia 74 of the ticket50 shown in FIG. 1. In the preferred embodiment, the circuit 81 includeseight resistor tracks 82-96 which are divided into two columns of fourresistor tracks each. Each resistor track 82-96 underlies the overprintareas 68 shown in FIG. 1 which define each of the play spot areas 72A-Hin FIG. 1. In addition, each resistor track 82-96 overlies a playindicia such as 74. Eight conductive or capacitive pick-up areas 98A-Hare located around the periphery of the resistor tracks 82-96 and acentral conductive track 100 is located between the two columns ofresistor tracks 82-96. The central conductive track 100 is connected toa conductive I-track shown at 102 which includes a terminal conductivebar 104 and a second conductive bar 106 parallel to and spaced apartfrom the terminal conductive bar 104. A resistive track 107 connects theterminal conductive bar 104 to the second conductive bar 106. In thefinal printed format, such as that shown in FIG. 1, the terminalconductive bar 104 underlies the bar code 80.

Each resistor track 82-96 is electrically connected to the centralconductive track 100 and to one of the conductive areas 98A-H, forexample, resistor track 82 is electrically connected to centralconductive track 100 and to conductive area 98A. The conductive areas98A-H and the central conductive track 100 are used to capacitivelycouple the ticket 50 to an electronic verification machine 108, such asthat illustrated in FIG. 14. In the preferred embodiment, eachconductive area 98A-H acts as a capacitor plate, the other capacitorplate being provided by the electronic verification machine 108. Inaddition, the central conductive track 100 also acts as a capacitorplate, the second capacitor plate being provided by the electronicverification machine 108. The capacitive coupling of the conductiveareas 98A-H and the central conductive track 100 to the electronicverification machine 108 completes the printed circuit 81 and permitsthe electronic verification machine 108 to excite the circuit and tomeasure the electrical signature or signatures of ticket 50. Since thecapacitive coupling of the conductive areas 98A-H and the centralconductive track 100 to the electronic verification machine 108 permitsthe electronic verification machine 108 to measure the electricalsignature(s) of ticket 50, areas 98A-H and track 100 are also known ascapacitive pick-up areas because through these areas the electronicverification machine 108 “picks-up” the electrical signature of ticket50.

Because each of the resistor tracks 82-96 is electrically connected toboth the central conductive bar 100 and to one of the conductive areas98A-H, each of the resistor tracks 82-96 forms a complete circuit whenthe ticket 50 is coupled to the electronic verification device 108. Thuseach of the resistor tracks 82-96 has its own electrical signature equalto the printed resistance of the resistor track. As shown in FIG. 2,each of the four resistor tracks in the two columns has the sameresistance. Since each of the resistor tracks 82-96 is electricallyconnected to its associated conductive area 98A-H, the integrity of theeight circuits containing the eight resistor tracks 82-96 can bedetermined by reference to the specific conductive area 98A-H used tomeasure the electrical signature. Alternatively, each resistive trackmay have a unique resistance. For example, the resistor track 82 canhave a resistance of 100 KΩ, the resistor track 84 can have a resistanceof 300 KΩ, the resistor track 86 can have a resistance of 500 KΩ, andthe resistor track 88 can have a resistance of 2700 KΩ. Similarly, theresistor tracks 90-96 can have resistances of 100 KΩ, 300 KΩ, 500 KΩ,and 700 KΩ respectively. As is explained in greater detail in SectionsIII and IV.C.1., the magnitude of the resistance for a specific resistortrack is a function of the type of ink used to print the resistor track,the length of the resistor track and the cross-sectional area, includingthe thickness, of the resistor track. Differences in the fourresistances 82-88 or 90-96 in a given column of resistor tracksfacilitate the determination of the authenticity and the integrity ofthe ticket 50 and more particularly can be used to determine which ofthe overprint areas 68 have been rubbed off.

Circuit 81, as shown in FIG. 2, is actually a composite of severallayers used to print ticket 50. The following section describes indetail the sequence and relationship of the various layers used to printticket 50.

III. Printing The Electrical Signature

In the preferred embodiment, the circuit 81 is printed onto the ticket50 preferable via a gravure printing process. The gravure printingprocess allows for the widest range of ink and coating formulations. Thegravure printing process, however, is not the only printing process thatcan be used to print the circuits. Gravure is only one type of intaglioprinting process. Other types of intaglio printing processes can be usedas well. In addition, the circuit 81 can be printed via screen printing,relief printing, planographic printing, letterpress and flexographicprinting. In the preferred embodiment, the ticket 50 is printed on apaper substrate. Paper substrates are preferred because they offer goodinsulation and absorbency. Alternatively, the ticket 50 could be printedon a plastic or a metal, such as an aluminum foil, substrate. If a foilsubstrate is used, portions of the foil can serve as the main conductorfor the ticket 50, while other portions of the ticket 50 are coveredwith an insulating layer.

FIG. 3 is a schematic diagram representing a gravure printing press 112suitable for printing ticket 50. The press 112 has fifteen gravureprinting stations 114-142 and one ink jet station 144. As is explainedin more detail below, each of the press stations 114-142 prints onelayer on the ticket 50 while the ink jet printer 144 prints the playindicia 74 and the bar code 80.

Station 114 prints a first layer or surface 146 which is shown in FIG.4. The first layer 146 is printed with a conductive-carbon based ink andforms a part of the circuit 81 shown in FIG. 2. The first layer 146includes two portions the first of which is an I-track 148. The I-track148 includes the terminal conductive bar 104 and the resistive track 107which form part of the I-track 102 illustrated in FIG. 2. A secondconductive bar 150 of the I-track 148 underlies the second conductivebar 106 of the I-track 102 of FIG. 2. The second portion of the firstlayer 146 consists of a pair of rows of blocking cells 152. Each of theblocking cells 152 is positioned to underlie one of the play indicia 74which are subsequently printed on the ticket 50.

The ink used to print the layer 146 should have a sheet resistivitybelow 2,700 Ω/□ preferably in the range of 1,000 Ω/□ to 1,300 Ω/□. Inthe ticket 50 shown in FIGS. 1-13, the ink used to print the lowerconductive layer 146 would most desirably have a sheet resistivity of1,200 Ω/□. “Sheet resistivity” (ρs), as that term is used herein, is thebulk resistivity of the ink (ρ) divided by the thickness of the film ofink (t) printed on the ticket 50.

ρs=ρ/t

Sheet resistivity (ρs) will typically be expressed in terms ofohms/square (Ω/□). In practice, the sheet resistivity of an ink isdetermined by printing and measuring the resistance of a unit length andwidth.

The resistance (R) of a specific resistor in turn is a function of thebulk resistivity of the material and the dimensions of the resistor:

R=ρ(1/tw)

where ρ is the bulk resistivity of the material used to make theresistor, 1 is the length of the resistor, t is the thickness of theresistor and w is the width of the resistor. Substituting the previousequation for sheet resistivity into the equation for resistance yieldsthe following:

R=ρs(1/w)

Thus, the resistance of a resistor printed with a conducting orsemi-conducting ink is a function of the sheet resistivity of the ink,the length of the printed resistor, and the width of the printedresistor. For example, the resistance of a printed resistor with an inkhaving ρs=100 Ω/□ which is 0.120 inches (0.3048 cm) long and 0.040inches (0.1016 cm) wide would be:

R=ρs(1/w)=100 Ω/□(0.0120/0.040)=300 Ω.

The ink used to print the first layer 146 should also have very goodadhesive properties so that the layer 146 adheres well to the ticket 50and should have good abrasion resistance properties so that the layer146 is not easily rubbed off the ticket 50. A preferred formulation forthe ink used to print the first layer 146 is given in Table 1.

TABLE 1 Preferred Ink Formulation For Layer 1 material wt % AcrylicResin 12-18% Pentaerythritol ester of 2-6% modified rosin Conductivecarbon 14-20% Polyamine amide/acidic 0.3-1.0% ester dispersant2-ethyhexyl diphenyl phosphate 2-5% plasticizer Anhydrous ethyl alcohol20-30% Normal Propyl acetate 23-33% 50/50 mixed solvent, normal 5%propyl acetate and ethyl alcohol 950 varnish 5%

The 950 varnish comprises 36.24% normal propyl acetate, 24.92% DM55acrylic, 12.92% pentalyn 830, 17.92% nitro varnish, and 3% santicizer141. The preferred formulation provides a film former, solvent basedink. Film formers are polymers capable of being plasticized to form acontinuous and totally flexible ink. In the preferred formulation, thesolvent evaporates from the printed surface during drying leaving acontinuous, conductive dry ink film. Preferably, the conductive carbonwill be about 2-20 μ in size in this formulation.

The first layer 146 serves at least two purposes. First, the solid blacknature of the blocking cells 152 of the first layer 146 serves toprevent unauthorized detection of the play indicia 74, for example, byshining a bright light through the ticket 50. Second, the I-track 148can be used to protect the bar code 80 against unauthorizedmodifications, by providing an electrical signature for the bar code 80which can be measured by the electronic verification machine 108. Itshould be noted that in some cases, especially where the ticket 50 doesnot include the blocking cells 152, it may be desirable to print anopaque blocking layer between the substrate 52 and the play indicia 74.

Station 116 prints the second layer 156 which is shown in FIG. 5. Thesecond layer 156 has two portions: an upper portion 156 a and a lowerportion 156 b. The upper portion 156 a overlies all of the blockingcells 152 of the first layer 146 shown in FIG. 4. The lower portion 156b overlies the terminal conductive bar 104 and the resistive track 107of the I-track 148 of the first layer 146. The gap between the upperportion 156 a and the lower portion 156 b exposes the second conductivebar 150 of the I-track 148 of the first layer 146. The second layer 156acts as a blocking layer to prevent the first layer 146 from obscuringobservation of the play indicia 74 when the ticket 50 is played. Asuitable formulation for the second blocking layer 156 is disclosed inU.S. patent application Ser. No. 08/004,157 the entire disclosure ofwhich is hereby incorporated by reference.

A third layer 158 is then printed by the printing station 118. Theplacement of the third layer 158 is essentially coincident with thesecond layer 156, as shown in FIG. 6. The third layer 158 also includesa upper portion 158 a and a lower portion 158 b separated by a gap whichexposes the second conductive bar 150 of the I-track 148. The thirdlayer 158 is a primer layer which provides a suitable surface forprinting the play indicia 74. A suitable formulation for the thirdprimer layer is disclosed in Walton, U.S. Pat. No. 4,726,608.

Printing stations 120-126 provide the features printed on the displayportion 54 of the ticket 50, as shown in FIG. 7. These printed featuresinclude the name 56 of the probability lottery game, information 58related to the rules for playing the game, and customized art work 60.Because 4 different printing stations 120-126 are used to print thesefeatures, as many as four different colors of ink can be used to printprocess colors.

The ink jet printer 144 prints the play indicia 74 on a portion of thethird layer 158, as shown in FIG. 8. In the preferred embodiment, thereare two columns of play indicia 74, each of which contains four separateplay indicia 74. The two rows of play indicia 74 are positioned so thateach separate play indicia 74 overlies one of the blocking cells 152 ofthe first layer 146 shown in FIG. 4. The ink jet printer 144 also printsthe inventory control number 70, the validation number 78, and the barcode 80 on the ticket 50. In the preferred embodiment, the inventorycontrol number 70, the play indicia 74, the validation number 78, andthe bar code 80 are printed with a water-based dye.

Printing station 128 prints the back 157 of the ticket 50 as shown inFIG. 9. The back 157 may include additional information 159 related tothe rules for playing the ticket 50.

The print station 130 prints a fourth layer 160 on the ticket 50. Thefourth layer 160 is indicated by the shaded portions in FIG. 10. Thefourth layer covers the upper and lower portions 158 a, 158 b of thethird layer 158 shown in FIG. 7, and also covers the play indicia 74,the inventory control number 70, the validation number 78, and the barcode 80. In the same manner as the second and third layers 156 and 158,the fourth layer does not cover the second conductive bar 150 of theI-track 148. The fourth layer 160 is a seal coat which protects theinventory control number 70, play indicia 74, the validation number 78,and the bar code 80 from abrasion and from liquids in which the playindicia 74, the validation number 78, and the bar code 80 are soluble.Suitable materials for this purpose include various polymer materialssuch as acrylics, polyester urethane, epoxy acrylate, and vinyl polymer.A suitable formulation for the third primer layer 158 of FIG. 6 isdisclosed in Walton, U.S. Pat. No. 4,726,608.

The print stations 132 and 134 print a fifth and a sixth layer 162 onthe ticket 50. As shown in FIG. 11, the fifth and sixth layers 162 areprinted as discrete sections which overlie the play indicia 74 and thevalidation number 78. The fifth and sixth layers 162 are indicated bythe shaded areas overlying the play indicia 74 and the validation number78. The fifth and sixth layers 162 are both substantially transparentrelease coats which allow the play indica 74 to be viewed by the playerand at the same time permit an easy removal of subsequent layers by, forexample, rubbing the ticket 50 with a fingernail. The same release coatformula on may be used to print both the fifth and sixth layers 162. Asuitable formulation for the third layer is disclosed in Walton, U.S.Pat. No. 4,726,608. Also, in some cases it may be desirable to use anultraviolet curable seal-release coat in place of the release coats 162.Such seal-release coats are well known in the art.

The print station 136 prints a seventh layer 164 which comprises theremainder of the electrical circuit 81 shown in FIG. 2 which is printedon the ticket 50. As illustrated in FIG. 12, the seventh layer 164 is apatterned layer which includes the resistor tracks 82-96 and theconductive areas 98A-H. The seventh layer 164 also includes theconductive bar 106 of the I-track 102 shown in FIG. 2. As explainedearlier, the resistor tracks 82-96 are connected to the conductive areas98A-H. The resistor tracks 82-96, as printed thus have electricalcontinuity with the conductive areas 98A-H and conductive track 100.

The relationship between the first layer 146 and the seventh layer 164is better understood with reference to FIGS. 19 and 20 which arerespectively plan drawings of the first layer 146 and of the seventhlayer 164 alone. As noted earlier, the first layer 146, shown by itselfin FIG. 19, consists of the blocking cells 152 and the I-track 148. TheI-track 148 includes the terminal conductive bar 104 and the resistivebar 107. The seventh layer 164, shown by itself in FIG. 20, consists ofthe resistive tracks 82-96, the conductive areas 98A-H, the centralconductive track 100 and the conductive bar 106. The seventh layer 164is positioned on the ticket 50 so that the conductive bar 106 of theseventh layer overlies the conductive bar 150 of the first layer 146 toform the partial circuit 81 as illustrated in FIG. 2. The overlyingrelationship of conductive bars 106 and 150 ensures electricalcontinuity between the first layer 146 and the seventh layer 164.

It is desirable that the ink used to print the seventh layer 164 have asheet resistivity at least in the range of 300 Ω/□ to 600 Ω/□ andpreferably, the sheet resistivity should be below 300 Ω/□. Severalparameters can be varied to reduce the sheet resistivity of an ink. Forexample, the shape and size of the conductive particles affects thesheet resistivity of the ink. In addition, metal pigments tend to reducethe sheet resistivity as does a high pigment to binder ratio. However,both metal pigment and a high pigment to binder ratio tend to reduce thegraphic adhesiveness of the ink. Unlike the ink used to print the firstlayer 146, the ink used to print the seventh layer 164 need not haveexceptional adhesive properties because the seventh layer 164 orportions thereof are designed to be removed to reveal the play indicia74 when the ticket 50 is played. Consequently, the ink used to print theseventh layer 164 on the ticket 50, or circuits on other types ofdocuments where the adhesive qualities of the ink are not a majorconsideration, can include metal particles and can have a relativelyhigh pigment to binder ratio. The use of metal particles in place of orin addition to carbon particles can substantiality increase theconductivity of the ink.

A preferred ink formulation for the seventh layer 164 is given in Table2.

TABLE 2 Preferred Conductive Ink Formulation For Layer 7 material wt %Acrylic resin 10-15% Pentaerythritol ester of 1-5% modified rosinconductive carbon  5-15% silver plated copper 10-25% particles (5-10 μ)polyamine amide/acid 0.25-0.75% ester dispersant anhydrous ethyl alcohol25-35% normal propyl acetate 28-38%

Although the preferred metal particles are sliver plated copperparticles, other conductive metal particles such as aluminum, brass,nickel, iron and iron oxide particles can be used as well. However, itshould be noted that nickel may not be suitable for use in certain typesof documents since it can be toxic if ingested. Also, in addition tosliver, the metal particles can be plated with gold or tin.

An eighth layer 168, preferably a scratch-off latex material, is appliedat printing station 138. As shown in FIG. 13, the eighth layer 168covers most of the playing field portion 62 of the ticket 50. The eighthlayer 168 does not cover the inventory control number 70 or the bar code80. The eight layer 168 does, however, overlie the conductive bar 102 ofthe seventh layer 164. The final printing stations 138, 140, and 142apply overprint graphics such as overprint areas 66, 68, and 76illustrated in FIG. 1. The square overprint areas 68 serve to visuallyidentify the individual play spot areas 72A-H and the overprint area 76,which overlies the validation number 78, is printed with the instruction“void if removed.”

IV. Measuring The Printed Electrical Signature

A. An Electronic Verification Machine

As stated earlier, the circuit 81 on the ticket 50 is completed when theticket 50 is capacitively coupled to the electronic validation orverification machine 108 which then can measure the electrical signatureof the circuit elements such as resistors 82-96 on the ticket 50. FIG.14 is a stylized perspective view of an exterior of the electronicverification machine 108. Although the exact configuration of theexterior of the electronic verification machine 108 can vary, theexterior of the electronic verification machine 108 has three features:a results indicator 174, a ticket interface 176, and a user interface178. As shown in FIG. 14, the results indicator 174 of the electronicverification machine 108 is a display panel 180. The display panel 180can display the results of a ticket validation operation and can alsodisplay the results of verification testing, including tests of theauthenticity and integrity of the ticket 50. The display panel 180 canalso display instructions, such as “Insert Ticket”, concerning the useof the electronic verification machine 108. In place of or incombination with the display panel 180, the electronic verificationmachine 108 can communicate with a printer 181 shown in FIG. 17 whichcan display the results of the ticket validation operation andverification testing as well. The user interface 178 can be a keyboardwhich the player or an agent can use to manually enter data from theticket into the electronic verification machine.

A ticket interface 176 of the electronic verification machine 108includes a ticket slot 182 into which the ticket 50 can be inserted.When the ticket 50 is properly inserted into the ticket slot 182, theconductive areas 98A-H, 100, and 106 are aligned with an array ofcapacitor plates 226A-H, 228 and 230, as shown in FIG. 18, locatedwithin the electronic verification machine 108, to complete the partialcircuit 81 printed on the ticket 50. In addition, the bar code 80 isaligned with a bar code reader 210 (not shown) located within theelectronic verification machine 108.

FIG. 15 is a stylized plan drawing of an alternative embodiment of anelectronic verification machine 183 having a different type of ticketinterface 177. In this embodiment the electronic verification machine183 has a hinged lid 184 which can be raised to expose the ticketinterface 177 which includes a ticket recess 186. Within the ticketrecess 186 is a sensor area 188 containing an array of capacitor plates(not shown) which align with the capacitor areas 98A-H, 100, and 106 onthe ticket 50. The ticket recess 186 also includes a bar code readerarea 190. The ticket 50 is placed within the ticket recess 186 such thatthe bar code 80 can be read through reader area 190 by a bar code reader210 located within the electronic verification machine 183 asillustrated in FIG. 17. The electronic verification machine 183 can alsohave a second sensor area 192 also containing capacitor plates (notshown) which align with the conductive areas 98A-H, 100, and 106 onticket 50.

FIG. 16 is a plan view of the preferred embodiment of the user interfacekeyboard 178. The user interface 178 includes a numeric key pad 196 anda set of operation keys 198-204. The operation key 200 is used to inputthe validation number 78 of the ticket 50 into the electronicverification machine 108 and the operation key 198 is used to manuallyinput the bar code 80 of the ticket 50 into the electronic verificationmachine 108. Keying in of the bar code 80 may be necessary if the barcode reader 210 is not able to read the bar code because, for example,the bar code 80 is damaged or perhaps has been tampered with.

FIG. 17 is a sectioned side view which includes a block diagram of themajor internal components of the electronic verification machine 108.The electronic verification machine includes the bar code reader 210,and a ticket sensor 212. The ticket sensor 212 senses when the ticket 50has been properly inserted so that the bar code 80 can be read by thebar code reader 210. When the ticket is properly inserted the conductiveareas 98A-H, 100, and 106 of the ticket 50 are aligned with a pair ofsensor plates, indicated at 214 and 216, which include an array ofcopper capacitor plates 226A-H, 228 and 230, shown in FIG. 18,positioned in a configuration which mirrors that of the conductive orcapacitor areas 98A-H, 100, and 106 of the ticket 50. The sensor plates214, 216 are part of a sensor head 218 which contains a set ofexcitation and detection circuitry for the electronic verificationmachine 108. The electronic verification machine 108 also includes aprocessor board 220, including a microprocessor and memory, and acommunications interface 222.

The excitation and detection circuitry of the sensor head 218 includes amicrocontroller 224 with associated memory as shown in FIG. 18. Themicrocontroller 224 provides the necessary logic to control theelectronic verification machine 108 and performs various tasks includingcontrolling the communications interface 222, the user interface 178,and the bar code reader 210. The microcontroller 224 also processes themeasured electrical signature of the circuit elements 82-96 on theticket 50 that can be used to determine the authenticity and integrityof the ticket 50. Because the microcontroller 224 requires relativelylittle processing power, a single, self-contained IC can be used toprovide inexpensive processing. Examples of acceptable chips include theMotorola 68HC711E9 and the Intel MCS®-51 Series microcontrollers. Eachof these chips includes a Random Access Memory (“RAM”) and aProgrammable Read Only Memory (“PROM”) and an Analog to Digitalconverter (“A/D”).

As is explained in greater detail below, in Section V., the bar code 80can include information regarding the value of the play indicia 74 ofthe ticket 50. The bar code reader 210 communicates directly with themicrocontroller 224 via an ANSI standard interface, for example, UART.In the preferred embodiment, the bar code reader 210 is a laser scanner.

The communications interface 222 generally is a serial digital interfacewhich may be a driver IC or a modem chip set. As is explained in moredetail in Section V. below, the serial digital interface 222 allows theelectronic verification machine 108 to communicate with a central hostcomputer 223 when necessary to determine the authenticity or integrityof the ticket 50. In the preferred embodiment, a non-standard interfaceor a low-level encryption is included in the design of the serialdigital interface 222 in order to enhance the security of communicationsbetween the electronic verification machine 108 and the central computer223.

In operation, the excitation and detection circuitry of the sensor head218 is capacitively coupled with the partial circuit 81 printed on theticket 50 to complete the circuit 81. Thus, a complete circuit 225including the partial circuit 81 on the ticket 50, as shown in FIG. 21,is completed 81 when the ticket 50 is placed within the ticket slot 182in the sensor head 218. It should be noted that the excitation anddetection circuitry can also be coupled to the ticket 50 by variousother methods including: direct coupling, inductive coupling, radiofrequency coupling and optical coupling, as described below in SectionIV.E.

In the preferred embodiment, the sensor head 218 of the electronicverification machine 108 is capacitively coupled to the circuit 81 onthe ticket 50 to complete the circuit 81. A block circuit diagram of thecompleted circuit 225 is shown in FIG. 21. As noted earlier, theconductive areas 98A-H, the central conductive track 100, and theconductive bar 106 function as capacitor plates. The sensor head 218includes an array of the capacitive coupler plates 226A-H, 228 and 230,arranged in the same configuration as the conductive areas 98A-H, 100and 106. When the ticket 50 is placed in the ticket slot 182, thecapacitor plates 226A-H are aligned with the conductive areas 98A-H, thecentral conductive track 100, and the conductive bar 106 to formcapacitors having an air gap dielectric. Alternatively, the capacitivecouplers 226A-H, 228 and 230 could be arranged within the electronicverification machine 108 so that the capacitor plates 226A-H, 228 and230 are positioned on the side of the ticket 50 opposite the conductiveareas 98A-H, 100 and 106. In this configuration, the capacitors formedby coupling the capacitive couplers 226A-H, 228 and 230 to theconductive areas 98A-H, 100 and 106 would have a dielectric contributedboth by the air gap and by the ticket substrate and printed layerslocated between the conductive areas 98A-H, 100, and 106 and thecapacitor plates 226A-H, 228 and 230.

As noted earlier, each of the resistor tracks 82-96 is capacitivelycoupled in series to one of the capacitor plates 226A-H in the sensorhead 218 via one of the conductive areas 98A-H. Similarly, a capacitoris formed by the capacitor plate 230 and the central conductive track100. In addition, the bar code resistor track 107 is connected in serieswith the capacitor formed by the capacitor plate 228 in the sensor head218 and the conductive bars 106 and 150 and to the capacitor formed bythe conductive track 104 and the capacitor plate 228.

The capacitor plates 226A-H and 228 are connected to a pair of bufferamplifiers 232 and 236. The main buffer amplifier 236 supplies a signalto an integrator 238 in the electronic verification machine 108 which inturn supplies a signal to the microcontroller 224. The secondary bufferamplifier 232 provides a feed back loop to the capacitor plates 226A-Hand 228 and hence the conductive areas 98A-H. The resistor tracks whichare not currently being tested by the electronic verification machine108 can produce stray capacitance which would interfere with themeasured detection signal. To overcome this effect, the secondary bufferamplifier 232 applies the buffered detection signal to the resistortracks which are not being tested, such as tracks 82-86, 90-96, and 107,to cancel out the effect of the stray capacitances.

The microcontroller 224 is also connected to a digital to analog (“D/A”)converter 240 which supplies a signal to a voltage controlled oscillator(“VCO”) 242. Because of the size constraints of a typical probabilitygame ticket, such as ticket 50, the capacitance formed by coupling theindividual resistor tracks, such as resistor track 88, to the excitationand detection circuitry is small. For example, a capacitor including aconductive track printed with the ink formulation described in Table 2and having an area of 0.201869 inches² would have a capacitance ofapproximately 9 pF. Consequently, the excitation and detection circuitryincludes an inductor 244 to oppose the effect of the capacitiveimpedance resulting from the small capacitance provided by coupling thecapacitive pick-up areas 98A-98H and 104 to the electronic verificationmachine 108. The output from the VCO 242 is routed through the inductor224 and applied to the central conductive track 100 via the excitationcoupler 230.

When the ticket 50 is inserted into the electronic verification machine108 and the microcontroller 224 is activated, the electronicverification machine 108 begins a discreet verification process for eachresistor track 82-96 and 107. The microcontroller 224 steps an 8-bitoutput bus 245, which controls the D/A converter 240, from a value of255 to zero. The DC output voltage from the D/A 240 is then applied tothe VCO 242 for conversion to frequency. Thus, the microcontroller 224produces a stepped series of decreasing excitation frequencies. Thesestepped excitation frequencies are routed though the inductor 244 andapplied to the central conductive track 100 of the ticket 50 via theexcitation coupler 230. The excitation signal from the VCO 242 isultimately applied to each of the eight resistor tracks 82-96 and thebar code resistor track 107. The microcontroller 224 selects anindividual resistor track, such as resistor track 88, through solidstate switches (not shown) and routes the capacitively coupled detectionsignal to the dual buffer amplifiers 232 and 236. The main bufferamplifier 236 supplies a buffered voltage to the integrator 238 whichconverts the AC detection signal to a DC detection signal and appliesthis DC detection signal to the analog to digital input of themicrocontroller 224 for processing.

In this embodiment, the electronic verification machine 108 uses aiterative resonance seeking algorithm to determine the measuredelectrical signature for each of the resistor tracks 82-96 and 107. Tworegisters (not shown), the resonance register and the temporaryregister, in the microcontroller 224 are used to store successive valuesof the detection signal. The detection signal is the signal producedwhen any of the resistor tracks, such as resistor track 88, is coupledto the electronic verification machine 108 and receives the excitationsignal via the central conductive bar 100. The contents of both theresonance and temporary registers are initially set to zero.

The amplitude of the detection signal is ultimately converted to aneight-bit binary value via the integrator 238 and the A/D input of themicrocontroller 224. The binary converted detection signal is thenstored in the temporary register of the microcontroller 240. and themicrocontroller 240 then compares the contents of the two registers. Ifthe contents of the temporary register is less than the contents of theresonance register, the resonance register contains the binary convertedequivalent of the amplitude corresponding to the resonance frequency ofthe resistor track being tested, such as track 88. Consequently, thefrequency of the excitation signal and the contents of the resonanceregister are output to the processor 220 and in certain cases to thecommunication interface 222 which includes a UART serial digital port.The output of the communication interface 222 which represents theelectrical signature of the resistor track being tested can betransmitted to the central computer 223 or to a lottery terminal (notshown).

If the resonance frequency of the resistor track, such as track 88, isnot detected, the above excitation and detection process is repeated.First, the contents of the temporary register are stored in theresonance register. Thereafter, the 8-bit output bus, which controls theD/A converter 240, is decremented to produce an excitation signal fromthe VCO 242 having a lower frequency than the previously appliedexcitation signal. The new excitation signal is applied to the ticketvia the conductive track 100 and the new detection signal is compared,as previously described, with the contents of the resonance register.This excitation and detection process is repeated for each resistortrack 82-96 and 107 until the detection signal corresponding to thatassociated with the resonance frequency of the resistor track beingtested is determined.

B. Candidate Circuits For Providing The Electrical Signature

1. The T-Square Circuit

Several different types of circuit configurations can be printed on theticket 50 to provide a measurable electrical signature. In the preferredembodiment, the printed circuit configuration 81, termed a T-squarecircuit, is illustrated in FIG. 2. As noted earlier, each of theresistor tracks 82-96 is electrically connected to one of the conductiveareas 98A-H and to the central conductive track 100. FIG. 20 is a plandrawing of the partial printed circuit used to determine theauthenticity and integrity of the play spot areas 72A-H and illustratesthe resistor tracks 82-96 connected to the conductive areas 98A-H andthe central conductive track 100. In addition, the bar code resistortrack 107 is electrically connected to the conductive bars 104 and 106.FIG. 19 is a plan drawing of the partial printed circuit used todetermine the authenticity and integrity of the bar code 80 andillustrates the bar code resistive track 107 connected to the conductiveareas 104 and 150. As noted earlier, the first layer 146 printed on theticket 50 includes the bar code resistor track 107 and the conductiveareas 150 and 104. Successive layers, up to and including the sixthlayer 162, do not overlie the conductive area 150 thus leaving theconductive area 150 exposed. The seventh layer 166 consists of thepartial printed circuit used to determine the authenticity and integrityof the play spot areas 72A-H, as shown in FIG. 20. The conductive bar106 of the seventh layer 164 immediately overlies the conductive bar 150of the first layer 146. Consequently, the partial circuit includingcircuit elements 82-96 and 98A-98H for the play spot areas 72A-H, shownin FIG. 20, and the partial circuit for the bar code 80, shown in FIG.19, are electrically connected via the conductive bars 106 and 150.Thus, when the ticket 50 is coupled to the electronic verificationmachine 108, the excitation signal applied to the ticket 50 via thecentral conductive track 100 is also transmitted to the bar coderesistive track 107 via the conductive bars 106 and 150. Therefore, thecompleted circuit 225 which is formed when the ticket 50 is capacitivelycoupled to the sensor head 218 via the conductive areas 98A-H, 100, 104,and 106 is actually nine different, separate circuits, one for each ofthe resistor tracks 82-96 and one for the bar code resistor track 107.

As is explained in Section V. below, the electronic verification device108 tests the integrity of a specific resistor track, such as resistortrack 88, by comparing the measured resistance to the resistance whichshould result from the undisturbed configuration of the resistor trackas originally printed, that is, the predetermined electrical signatureof the resistor track. If the play spot area overlying the resistortrack, such as track 88, has not been altered, for example, rubbed offor lifted to reveal the underlying play indicia, the resistance measuredby the electronic verification machine 108 will be substantially thesame as the resistance which should result from the configuration of theresistor track 88 as originally printed. If, however, the play spot hasbeen removed or lifted, the measured resistance will be substantiallydifferent than the predetermined electrical signature of the track 88.

The T-square circuit 200 can determine the authenticity and integrity ofthe ticket 50 as a whole, of the individual play spot areas 72A-H, andof the bar code 80. If no resistance can be measured for any of theresistor tracks 82-96, it can be assumed that either the ticket 50 is acounterfeit or that all of the play spot areas 72A-H have been rubbedoff thereby rendering the ticket 50 void. Moreover, because the T-squarecircuit 200 provides a different individual circuit for each of theresistor tracks 82-96, the T-square circuit 200 can individually testthe integrity of the individual play spot areas 72A-H.

For example, a particular probability game may require revealing threematching game indicia to win. In addition, the game rules may requirethat no more than three play spot areas be rubbed off to reveal theunderlying indicia. Consider the hypothetical situation in which anindividual presents the ticket 50 to a lottery agent for redemptionbecause the individual has ostensibly rubbed off only three play spotareas and the indicia in the three play spot areas match. By pure visualinspection, the ticket 50 might appear to be a valid and winning ticket.However, when the ticket 50 is inserted into the ticket slot 182 of theelectronic verification machine 108 to measure the resistance of theplay spot areas 72A-H, the electronic verification machine 108 woulddetermine that not only the measured resistances of the three rubbed-offplay spot areas differ from the predetermined resistances for these playspot areas, but also that the measured resistance of other“non-rubbed-off” play spot areas differ from the predeterminedresistances for these areas. This situation could arise, for example,when the individual removes the overprint areas 68 of these additionalplay spot areas to reveal the hidden indicia 74 and then attempts toreplace the overprint areas 68 so that these play spot areas appear tonot have been played. Thus, although visually the ticket 50 appears tobe a valid winning ticket, the measure of the resistances 82-96 wouldindicate that more than three play spot areas have been removed and thattherefore the ticket 50 is void. In addition, if the measured resistanceof the bar code resistor track 107 is substantially different from thepredetermined electrical signature for the bar code 80. it can beassumed that the bar code 80 has been tampered with as well.

2. The Binary Coupled Circuit

An alternative embodiment of a ticket 250 having a partial printedcircuit 252, termed a binary coupled circuit, is shown in FIG. 21. Thepartial circuit 252 is analogous to the seventh layer 164 printed on theticket 50. As with ticket 50, the partial circuit 252 is ultimatelyprinted on a ticket substrate 254 preferably using a conductive ink ofthe type described in Table 2. Although not shown, it is to beunderstood that additional layers such as a lower conductive layeranalogous to the first layer 146 of ticket 50, a blocking layer and aprimer layer analogous to the second layer 156 and third layer 158 ofthe ticket 50, play indicia analogous to the play indicia 74 of ticket50, a seal coat and release coats analogous to the fourth layer 160 andthe fifth and sixth layers 162 of the ticket 50 are also printed on theticket 250 between the substrate 254 and the partial circuit 252 in amanner similar to that used for ticket 50.

The ticket 250 includes a display portion 256 and a playing fieldportion 258. The display portion 256 is ultimately covered by a coating(not shown) suitable for receiving customized graphics (not shown) andinformation (not shown) related to the rules for playing the ticket 250.The playing field portion includes two columns of four, separatelyremovable play spot areas 260-274. Within the playing field portion 258,the partial circuit includes several conductive areas 276-292 and eightresistor tracks 294-308. Each of the play spot areas 260-274 ispositioned between two conductive areas, for example, play spot area 260is positioned between conductive areas 276 and 278 and play spot area262 is positioned between conductive areas 278 and 280. Each of theresistor tracks 294-308 is also positioned between and electricallyconnected to two of the conductive areas 276-292. For example, resistortrack 294, associated with play spot area 260, is positioned between andconnected to conductive areas 276 and 278. Underlying each of the playspot areas 260-274 is a conductive line (not shown). Each conductiveline is connected to the two conductive areas associated with itsrespective play spot area and resistor track. For example, theconductive line underlying play spot area 260 is connected to conductiveareas 276 and 278.

The three additional conductive areas 310-314 are printed in the displayportion 256 of the ticket 250. The first conductive area 310 isconnected to the first column of four play spots 269-266 via aconductive track 316 connected to the conductive area 284. The secondconductive area 312 is connected to the second column of four play spots268-274 via a second conductive track 318 connected to the conductivearea 292. All eight play spot areas 260-274 are connected to the thirdconductive area 314 via a third conductive track 320 connected to theconductive area 276. The conductive areas 310-314 serve as capacitorplates when the ticket 250 is coupled to an electronic verificationmachine.

Each column of four play spot areas 260-266 and 268-274 forms onecomplete circuit when the ticket 250 is coupled to the electronicverification machine 108. The excitation signal from the electronicverification machine 108 is routed through each group of four play spotareas 260-266 via the common conductive area 314 in the display portion256 of the ticket 250. Each group of four play spot areas 260-266 and268-274 provides its own detection signal. The detection signal for theplay spot areas 260-266 is coupled to the electronic verificationmachine 108 via the conductive track 316 and the conductive area 310.The detection signal for play spot areas 268-274 is coupled to theelectronic verification machine 108 via the conductive track 318 and theconductive area 312.

Within a group of four play spot areas, for example play spot areas260-266, the magnitude of the detection signal varies with the integrityof each of the play spot areas 260-266. If the play spot areas 260-266are intact, the excitation signal is substantially unaltered and isrouted through the conductive lines underlying each of the play spotareas 260-266. However, if a play spot area has been rubbed off orlifted to reveal the underlying play indicia, the signal is routedthrough the resistor track associated with that play spot area. Forexample, if play spot area 260 is intact, the signal proceeds throughthe underlying conductive bar to the conductive area 278. However, ifthe play spot area 260 has been at least partially removed to reveal theunderlying play indicia, the circuit through the conductive line isbroken thus routing the signal through the associated resistor track 294thus changing the characteristics of the detection signal.

In the preferred embodiment of this ticket 250, each of the resistortracks associated with a group of four play spot areas, such as theresistor tracks 294-300 associated with play spot areas 260-266 has aunique predetermined resistance that is related, in a binomialprogression, to the other resistor tracks in the column. For example,resistor track 294 can have a predetermined electrical signature equalto a resistance of 100 KΩ, resistor track 296 can have a predeterminedelectrical signature equal to a resistance of 200 KΩ, resistor track 298can have a predetermined electrical signature equal to a resistance of400 KΩ, and resistor track 300 can have a predetermined electricalsignature equal to a resistance of 800 KΩ. The resistor tracks, such asresistor tracks 294-300, are printed in parallel to the conductive linesunderlying the play spot areas, such as play spot areas 260-266. Asexplained below, the binomial relationship of the printed resistancesfor each resistor track within a group of four resistors tracks permitsdetermination of the integrity of each play spot even though only onedetection signal is produced for all four resistor tracks.

FIG. 22 is a partial schematic circuit diagram 324 illustrating thecoupling of one column of four resistor tracks 260-266 to the excitationand detection circuitry of the electronic verification machine 108. Theparts of the circuit which are contributed by the ticket 250 include thefour resistor tracks 294-300, the conductive areas 276-284, theconductive lines 316 and 320, and the conductive areas 314 and 310. Inaddition, the ticket partial circuit includes four conductive lines326-332 which underlie the play spot areas 260-266. The play spot areas260-266 do not actually form a part of the circuit but are included inFIG. 22 for ease of understanding.

The remainder of the excitation and detection circuit is provided by theelectronic verification machine 108, including a pair of capacitorplates 334 and 336. The capacitor plates 334 and 336 can consist of, forexample, copper plates positioned within the electronic verificationmachine 108 to mirror the configuration of the conductive areas, such asconductive areas 310 and 314, on the ticket 250. When the ticket 250 iscoupled to the electronic verification machine, the excitation anddetection circuit is completed by the capacitive coupling of thecapacitor plates 334 and 336 in the electronic verification machine withthe conductive areas 314 and 318 printed on the ticket 250. Theexcitation signal is applied to the ticket 250 via one of the capacitorsformed by one of the capacitor plates, for example the capacitor 334,with the conductive area 314 printed on the ticket 250. The detectionsignal is routed to the rest of the excitation and detection circuit viathe capacitor formed by the other capacitor plate in the electronicverification machine, for example plate 338, with the conductive area310 printed on the ticket 250.

When the play spots 260-266 have not been removed or tampered with, asillustrated in FIG. 22, the excitation signal flows through the each ofthe four conductive lines 326-332. However, removing or partiallyremoving one of the play spots 260-266 effectively breaks the circuitthrough the associated conductive line rerouting the signal through theassociated resistor track. For example, if play spot 260 is removed, thesignal pathway would go through resistor track 294. Because eachresistor track 294-300 has its own unique resistance, each resistortrack 294-300 produces its own unique detection signal therebypermitting the electronic verification machine 108 to identify which, ifany of the play spot areas 260-266 have been lifted or removed.Moreover, since the resistance values of the resistor tracks 294-300 arerelated to each other as a binomial progression, the electronicverification machine 108 can also identify which of the play spots260-266 have been removed when two or more of the play spots 260-266have been removed. For example, if both play spots 260 and 262 areremoved the combination of resistor tracks 294 and 296 adds 300 KΩ tothe excitation and detection circuit. However, if play spots 260 and 264are removed, the combination of resistor tracks 294 and 298 adds 500 kΩto the excitation and detection circuit. Thus, because the resistortracks 294-300 have resistance values that are related as a binomialprogression, each possible combination of resistor tracks 294-300results in a unique total resistance which can be used to identify theplay spots 260-266 that have been removed. Table 3 lists all thepossible combinations of resistor tracks 294-300 and the resultingresistance values for the previously identified resistance values forthe resistor tracks 294-300.

TABLE 3 Resistor Combinations Resistors In The Circuit EffectiveResistance R1 100 R2 200 R3 400 R4 800 R1 + R2 300 R1 + R3 500 R2 + R3600 R1 + R2 + R3 700 R1 + R4 900 R2 + R4 1000 R1 + R2 + R4 1100 R3 + R41200 R1 + R3 + R4 1300 R1 + R3 + R4 1400 R1 + R2 + R3 + R4 1500

Additional resistance values and combinations of resistance values arepossible. For example, the resistance values in Table 3 could beincreased or decreased by an order of magnitude. The principle of thiscircuit design is that the individual resistance of each resistor trackwithin a group of resistor tracks, such as resistor tracks 294-300,should be algorithmically related to the resistances of the otherresistor tracks within the group so that every combination of resistortracks provides a unique total resistance. Preferably, the individualresistances should vary as a binomial progression.

3. The Infinite Resistance Circuit

FIGS. 23, 24, 25 and 26 illustrate another partial printed circuit whichcan be used to validate and determine the authenticity and integrity ofa document which in this example is a lottery ticket 340. As shown inFIG. 23, the lottery ticket includes play indicia 342 which are printedover the ticket substrate 344. Additional information, such as the nameof the lottery game 346 and rules 348 for playing the ticket are alsoprinted on the ticket substrate 344. FIG. 24 is a plan drawing of thescratch-off coating 350 which is printed over and conceals the playindicia 342. The scratch-off coating 350 is a removable layer of amaterial such as latex which can be relatively easily removed to revealthe play indicia 342. A single block of scratch-off coating 350 is usedto cover all of the play indicia 342. A release coat (not shown)coincident with the scratch-off coating 350 is also printed on theticket 340 between the play indicia 342 and the scratch-off coating 350.FIG. 25 is a plan drawing of the partial printed circuit which is usedto determine the integrity and authenticity of the ticket 340. Thecircuit consists of a single conductive area indicated at 352A and 352Bwhich overlies the scratch-off coating 350. The two portions 352A, 352Bof the conductive area extend beyond the edges of the scratch-offcoating 350. FIG. 26 is a plan drawing of the ticket 340 in its finalprinted state which includes overprint areas 354 that conceal thescratch-off coating 350 and the conductive area 352, as well asoverprint areas 356 that define the individual play spot areas.

When the ticket 340 is coupled to the electronic verification machine108 the portions 352A and 352B serve as capacitor plates to couple thepartial circuit printed on the ticket 340 with the excitation anddetection circuitry in the electronic verification machine 108. Theportion of the conductive track 352A-B which immediately overlies thescratch-off coating 350 but does not extend beyond the scratch-offcoating 350 serves as a resistor track when the ticket 340 is coupled toan electronic verification machine 108. If the ticket is in its originalintegral state, the portion of the conductive area 352A-B immediatelyoverlying the scratch-off layer 350 is electrically connected to theportions 352A and 352B which serve as capacitor plates. However, if anindividual has attempted to surreptitiously inspect the play indicia 342by, for example, lifting and then replacing the scratch-off layer 350,the electrical connection between the middle portion of the conductivelayer and the end portion 352A and 352B would be broken resulting in anopen circuit.

4. The Increased Resistance Circuit

FIG. 27 illustrates an alternative embodiment of a scratch-off layer 358for the ticket 340. Unlike the previously described scratch-off layer350, the scratch-off layer 358 consists of discreet, individual areaswhich overlie each play indicia 342 (not shown). A release coat (notshown) underlies each of the discreet portions of the scratch-offcoating 358. The partial printed circuit which overlies the scratch offlayer 358 consists of a single conductive area indicated at 360A and360B which overlies all of the scratch off layer 358. Two portions 360A,360B of the conductive area 360 extend beyond the area of the ticket 340containing the scratch-off coating 358. The final printed format of theticket 240 is shown in FIG. 26 and includes overprint areas 354 thatconceal the scratch-off coating 358 and the conductive area 360A-B, aswell as overprint areas 356 that define the individual play spot areas.

When the ticket 340 is coupled to an electronic verification machine108, the portions 360A and 360B of the conductive area 360 which extendbeyond area of the ticket 340 containing the scratch-off layer 358 serveas capacitor plates to couple the partial circuit printed on the ticket340 with the excitation and detection circuitry in the electronicverification machine 108. The portion of the conductive area 360A-Bwhich immediately overlies the scratch-off coating 358 but does notextend beyond the scratch-off coating 358 serves as a resistor trackwhen the ticket 340 is coupled to the electronic verification machine108. If all of the play spots are intact, the electrical signature ofthe ticket 340 will be equal to the printed resistance associated withthe portion of the conductive track 360 which overlies all of the playindicia 342. However, if an individual has attempted to surreptitiouslyinspect the play indicia 342 by, for example, lifting and then replacingone portion of the scratch-off layer 358, the small portion of theconductive area 360A-B immediately overlying the removed area of thescratch-off layer 258, will be electrically disconnected from theremainder of the conductive area 360A-B, leading to an increase in theresistance associated with the conductive area 360A-B.

5. The Waffle Circuit

FIG. 29 is a plan drawing of another partial circuit 364 which can beprinted on a lottery ticket to determine the authenticity and integrityof the play spot areas. The partial circuit, termed a waffle circuit,includes two conductive bars 366 and 368 which are electricallyconnected to a conductive area 370 overlying the play indicia (notshown). Removable scratch-off areas 372 overlie the portions of theconductive area 370 which immediately overlie the individual playindicia. A seal coat and release coats analogous to the forth layer 160and the fifth and sixth layers 162 of the ticket 50 in FIG. 11 areprinted in an appropriate configuration between the play indicia and theconductive area 370. Thus, removal of any of the scratch-off areas 372also removes a portion of the conductive area 370. When the ticket whichincludes the partial circuit 364 is coupled to the electronicverification machine 108, each of the play spot areas defined by thescratch-off areas 372 serves as a capacitor plate. In addition, theconductive bars 366 and 368 also serve as capacitor plates to couple thepartial circuit 364 to the excitation and detection circuitry of theelectronic verification machine 108. The excitation and detectioncircuitry of the electronic verification machine 108 in turn includes anarray of capacitive couplers which are positioned to mirror theconfiguration of the conductive bars 366 and 368 and the scratch-offareas 372. Thus, in contrast to the previously described partialcircuits in FIGS. 20, 21, and 23-28, the electrical signature of theplay spot areas associated with the partial circuit 364 is a conductivetrack, rather than a resistive track.

The electronic verification machine 108 can check the authenticity andintegrity of the play spot areas defined by the scratch—off areas 372 byapplying an AC excitation signal to one of the conductive bars 366 or368. If the individual play spot area being tested is intact, theexcitation signal will be routed through the portion of the conductivearea 370 underlying the scratch-off area 372 associated with the testedplay spot area. Consequently, an AC detection signal will be routed tothe capacitor plate in the electronic verification machine 108 whichmirrors the particular play spot area 372. However, if the scratch-offarea 372 being tested has been at least partially removed, theassociated removal of a portion of the conductive area 370 creates anopen circuit under that particular scratch-off area 372. Hence, no ACdetection signal is routed to the associated capacitor plate in theelectronic verification machine 108, indicating that the integrity ofthe play spot area 372 has been changed.

6. The Recursive Circuit

FIG. 30 is another plan drawing of a partial printed circuit 376 whichcan be used to determine the authenticity and integrity of the play spotareas of a lottery ticket. The partial circuit 376 includes resistortracks (not shown) which underlie each of the removable scratch-offareas 378. Each resistor track is electrically connected to a pair ofconductive bars 380A and 380B. In the partial circuit shown in FIG. 30,there are a total of twenty-four conductive bars 380A, 380B, two forevery resistor track associated with one of the scratch-off areas 378.When the ticket which includes the partial circuit 376 is coupled to anelectronic verification machine 108, each resistor track associated witheach scratch-off area 378 is capacitively coupled to the excitation anddetection circuity of the electronic verification machine 108 by itsassociated conductive bars 380A and 380B. One conductive bar, forexample, bar 380A, is used to apply the excitation signal to theresistor track. The second conductive bar, for example bar 380B, routesthe detection signal to the rest of the excitation and detectioncircuitry in the electronic verification machine 108. If the scratch-offarea 372 being tested is intact, the electrical signature of theassociated resistor track will be substantially equal to the printedresistance of the resistor track underlying the scratch-off area 372.If, however, the scratch-off area 372 being tested has been at leastpartially removed or lifted, the measured resistance of the resistortrack and hence the resonant frequency of the completed circuitassociated with the scratch-off area 372 will be substantially differentthan the printed resistance of the resistor track.

C. Variation In Printed Resistances

1. Variations In The Printed Resistances

A number of the foregoing circuits, such as the T-square circuit shownin FIG. 20, and the binary-weighted circuit shown in FIG. 21, use theresistance of a printed resistor track to impart an electrical signatureto a document. As noted earlier, the resistance of such printed resistortracks can be defined as follows:

R=ρ(L/A)

where

R=resistance;

ρ=bulk resistivity (resistance per unit volume);

L=length of resistor; and

A=cross sectional area of the resistor.

The cross-sectional area of the resistor in turn equals the product ofthe print thickness (t) and the width (W) of the resistor. Substitutingthese parameters yields the following formula for the resistance of aprinted resistor track:

R=ρ(L/tW)

Thus the resistance of a printed resistor track such as those used inthe previously described circuits is a function of the bulk resistivityof the ink used to print the resistor, the length of the resistor track,the thickness of the printed track and the width of the printed track.Resistor tracks having different resistances can thus be formulated byvarying any of these parameters. In practice, changing the resistivityof the inks used in order to create different resistor tracks havingdifferent resistances may be impractical because, at least in a gravureprinting process, changing inks requires using a different printingstation. The other parameters, however, can be easily and effectivelyvaried to provide different resistor tracks within one circuit whichhave different resistances. FIG. 31 is a plan drawing of four differentresistor tracks 384-390. Because the length and widths of the resistortracks 384-390 differ, the resistances of the resistor tracks 384-390will be different even if the resistor tracks 384-390 are printed withexactly the same conductive ink. Thus, for example, the resistor tracks386 and 388 would have different resistances even though the lengths ofthe resistor tracks 386 and 388 are approximately equal because thewidths of the resistor tracks 386 and 388 are not the same. Thus, theresistance of the resistor tracks printed on a document, such as theticket 50, can be varied by varying the dimensions of the printedresistor tracks.

2. Variations In The Measured Resistances

Variations in ink resistivity can also occur over the course of a largeprint run. These variations in resistivity are due to a number offactors including printing process temperature and viscosity variations.Consequently, these variations are only detectable over a large numberof tickets that were printed over a long period of time. The resistivityof the ink on a single ticket does not fluctuate in this manner.However, the resistance of a resistor track printed at the beginning ofa print run can be measurably different than the resistance of anidentical resistor track printed with the same conductive ink at the endof a print run due to these time-dependent variations in the resistivityof the conductive ink. Consequently, it is desirable that these timedependent variations in the electrical signature be compensated for whenthe electronic verification machine 108 tests the authenticity andintegrity of the document.

The electronic verification machine, such as electronic verificationmachine 108, compensates for such time-dependent variations in themeasured electrical signature in one or both of two ways: (1) byestablishing that the measured values are accurate within a specifiedrange of an expected value; or (2) by using a separate circuit elementto establish the precision of the measured electrical signature.

In the preferred embodiment, the electronic verification machinecompensates for time dependent variations in the electrical signature bydetermining that the measured values are accurate within a range of, forexample, 10 percent, of the expected electrical signature. Thus, forexample, a measured resistance that is expected to be 500Ω would beacceptable as long as the resistance was in the range between 450Ω and550Ω. In other words, if the measured resistance was within this range,the corresponding play spot is treated by the electronic verificationmachine 108 as not having been rubbed off and therefore as being in itsoriginal integral state as well as presumably authentic.

If the time dependent variations in the electrical signature arecorrected by using a precision system, the partial circuit printed onthe ticket must contain an additional element, a calibration line, whichis used to determine if a measured resistance is precise. FIG. 32 is aplan drawing of an alternative embodiment of a T-square circuit 392which includes a calibration line shown generally at 394. Thecalibration line 394, termed a John Galt line, includes a resistor track396 connected to a conductive area 398. The remaining elements of thepartial printed circuit 392 are analogous to and function in the samemanner as the T-square circuit shown in FIG. 20. Hence, the remainingelements of the circuit 392 in FIG. 32 correspond to the circuitelements shown in FIG. 20. The calibration line 394 is connected to therest of the circuit 392 via the central conductive area 100. Theresistor track 396 is printed on a portion of the ticket which does notinclude play spot areas. Consequently, the resistor track 396 shouldremain in its original integral state after the ticket has been played.When a ticket containing the calibration line 394 is coupled to theelectronic verification machine 108 the resistor track 396 is coupled tothe excitation and detection circuitry of the electronic verificationmachine 108 by the capacitors formed by coupling the conductive areas100 and 398 to capacitor plates in the electronic verification machine108.

In the partial circuit 392 shown in FIG. 32, the calibration line 394 isused to determine how far the measured resistances of a particularticket should deviate from the expected value for these resistances. Forexample, if the calibration line 394 is printed with an expectedresistance of 500Ω, but measured resistance of the calibration line 394on a particular ticket actually has a calibration value resistance of525Ω, the five percent increase over the expected value should be seenin other resistances on the card as well. Therefore, even if a measuredresistance of a play spot area is within the acceptable value of 10percent above or below the expected value, it should be approximatelyfive percent higher than the expected value in order to be precise forthis ticket. Thus, if a given resistance corresponding to one of theplay spots is eight percent below the expected value and thereforewithin plus or minus ten percent of the expected resistance, the spotwould be deemed to have been played because the resistance, althoughaccurate, is not within the calibrated precision for this ticket.

D. Protection Of The Bar Code

A circuit printed on a lottery ticket, such as the circuit 81 printed onthe ticket 50 shown in FIG. 2, can include a partial printed circuitwhich provides an electrical signature to protect the bar code 80. Asnoted with reference to FIG. 19, the bar code partial circuit includes aresistor track 107 connected to two conductive areas 150 and 104. Inaddition, the conductive area 150 immediately underlies the conductivearea 106 of the partial printed circuit 164 used to determine theauthenticity and integrity of the play spot areas, as shown in FIGS. 2and G. Hence the partial printed circuit for the bar code 80 and thepartial printed circuit 164 for the play spot areas are electricallyconnected via the overlying relationship of the conductive areas 106 and150. Consequently, when the electronic verification machine 108transmits the excitation signal to the ticket 50 via the centralconductive track 100, the excitation signal can be routed to the barcode partial circuit via the conductive areas 106 and 150. The detectionsignal from the bar code 80 is routed to the remaining excitation anddetection circuitry via the capacitor formed by the conductive area 104and a capacitor plate in the electronic verification machine 108.

The bar code 80 is in turn printed on the ticket 50 to at leastpartially overlie the bar code partial circuit. In the preferredembodiment shown in FIGS. 1 and 2, the bar code 80 is printed on theticket 50 so that it overlies the conductive area 104. Alternatively,the bar code 80 could be printed to overlie the resistor track 107. Ineither embodiment, attempts to alter the bar code 80, for example bysubstituting the bar code 80 of the ticket with the bar code of adifferent ticket, would result in changes in the measured electricalsignature of the bar code 80 by changing either the resistance or thecapacitance of the bar code partial circuit.

E. Alternative Circuit Designs

In addition to resistors, other types of electrical circuit elements canbe used in a printed circuit to produce electrical circuits. Forexample, the elements used to couple a document, such as the ticket 50,to an electronic verification machine 108 are not limited to capacitorplates or areas but can also include inductive, radio frequency, andoptical frequency circuit elements. In addition, the form of theelectrical signature can be varied so that a properties other thanresistance can be used to validate or determine the authenticity andintegrity of a document. Examples of alternative electrical signaturesinclude gain, amplitude, frequency, oscillation, and thermal effects.

1. Coupling

There are a number of methods by which a circuit printed on a document,such as the circuit 81 on the ticket 50, can be coupled to theelectronic verification machine 108 including direct, capacitive,inductive, radio frequency and optical coupling methods. In directcoupling, the ticket is coupled to the electronic verification machinevia direct physical contact of one or more conductive areas on theticket with an electrical element, such as a contact plate, within theelectronic verification machine 108. Although it is relativelystraightforward to implement, direct coupling has the potentialdisadvantage of signal distortions which can arise from surfaceimperfections or impurities on the conductive areas of the ticket.

In capacitive coupling one or more conductive areas such as the areas98A-H of the ticket 50 shown in FIG. 2 form one plate of a capacitor.The other plate of the capacitor is provided by a metal plate connectedto the circuitry of the electronic verification machine 108. Asdescribed previously, the resulting capacitor can be used to form partof a verification circuit 225 as shown in the block diagram of FIG. 18.Here the conductive areas 98A-C of the ticket 50 form capacitors withthe plates 200-204 of the electronic verification machine 108.

Inductive coupling is similar in that a ticket 400 is printed with acircular conductive area 402 as illustrated in the example of FIG. 33.The electronic verification machine 108 would then include a coil 404that is inductively coupled with the circular conductive area 402 whenthe ticket 400 is inserted in the electronic verification machine 108.There are a variety of configurations that can be used including anumber of inductors printed on the ticket 400 that would be inductivelycoupled with a corresponding number of coils in the electronicverification machine 108.

Radio frequency can also be used for verification as shown in FIG. 34.In this case a planar transmission line 406 is printed on a ticket 408which is separated by the ticket substrate 410 from a ground plane 412printed on the other side of the substrate 410. With this structureradio frequency energy is transmitted and received in a transverseelectromagnetic mode. Using this approach verification signals can betransmitted to the circuits printed on the ticket 408 from suitableantennas located in the electronic verification machine 108.

In addition, optical frequency can be used for verification where forexample a photo emitter conductor or semiconductor is printed on theticket 50 and is electrically stimulated to emit light at an infraredfrequency. Photo-detectors on the electronic verification machine 108can be used to detect and classify the frequency of the light emitted bythe ticket 50 in contrast to the nominal reflective background of theticket 50.

2. Signature Verification

There are a number of methods for verifying the authenticity orintegrity as well as to determine the redemption value of a lotteryticket, such as the ticket 50, using the electronic verification machine108. One method is to merely check for an open circuit in the circuitprinted on the ticket 50. Here a signal is applied to the ticket circuitby one of the techniques described above and if no current flow isdetected then it can be assumed that a play spot 72A-H has been removedor that the ticket has been tampered with.

Gain can also be used where the electronic verification machine 108includes an operational amplifier and the circuit element printed on theticket 50 serves in its feedback loop. The gain of the operationalamplifier will reflect any changes in the ticket circuit and thus can beused to detect tampering or to determine which play spots 72A-H havebeen scratched off by the player.

The amplitude of the voltage, current or power of the AC signal flowingthrough circuit printed on the ticket 50 can additionally be measured bythe electronic verification machine 108 to indicated changes in thecircuit that would reflect alterations in the ticket 50.

The phase of a signal flowing thought the circuit printed on the ticket50 can also be checked by the electronic verification machine 108against an expected or predetermined value to determine changes in thecircuit.

Frequency of the electrical signal induced in the circuit printed on theticket can be measured by the electronic verification machine to detectchanges in the ticket. This is an especially useful approach where thecircuit on the ticket 50 includes elements such as capacitors orinductors which can affect frequency.

A measure of oscillation frequency can also be used where the circuitprinted on the ticket combined with the circuit in the electronicverification machine forms 108 an oscillator or where a completeoscillator circuit is printed on the ticket 50. Here an expectedoscillation frequency can be used to detect changes in the ticket 50.

Thermal effects are another phenomena that can be used by the systemdescribed above to detect tampering or determine which play spots havebeen removed from a ticket 414 of the type shown in FIG. 35. In thiscase heat generated by current flowing though a set of resistors 416A-Dis detected by a group of infrared photodetectors 418A-D located in theelectronic verification machine 108. When one or more of a set of playspots 420A-D is removed current will no longer flow though itsassociated resistor and the resulting lack of infrared radiation wouldindicate that the spot(s) had been removed.

Capacitance and inductance changes in the circuits printed on the ticket50 can likewise be detected by the electronic verification machine 108indirectly from the frequency characteristics of the circuits in orderto determine whether changes have occurred on the ticket 50.

V. Validation of Lottery Tickets

Validation of the lottery ticket 50 as well as the determination theauthenticity and integrity of a document, such as ticket 50, can involvethe interaction of several steps. As an example, a description of apreferred method for validating the lottery ticket 50 of FIG. 1 usingthe electronic verification machine 108 of FIG. 14 is provided below.When an individual presents the ticket 50 to a lottery agent forredemption, the lottery agent insert the ticket 50 into the electronicverification machine 108. The electronic verification machine will readthe bar code 80, which contains the inventory control number andencrypted validation number data, and it will sense which of the playspots 72A-G have been removed. The lottery agent then enters thevalidation number 78 of the ticket 50 into the electronic verificationmachine 108 via the user interface 178. As noted earlier, the validationnumber 78 contains information related to the identity of a specificticket, such as the pack and ticket number. In addition, in thepreferred embodiment the validation number 78 also contains informationrelated to the electrical signatures of the circuit elements printed onthe ticket 50. For example, the ticket 50 has two electrical signatures.One signature is the expected resistance of the bar code resistor track107. The second is the expected resistance of the play spot resistortracks 82-96 which all have the same value. If the play spot resistortracks had different expected values, such as the resistor tracks294-308 in the partial circuit 292 shown in FIG. 21, information relatedto each electrical signature could be stored in the validation number 78of the ticket 50. Alternatively, the information related to theelectrical signature(s) of the circuit elements printed on the ticket 50could be stored in a look-up table in the microprocessor on theprocessor board 220 in the electronic verification machine 108 or thecentral computer 223. In this case, the validation number 78 or theencrypted validation number printed in the bar code 80 is used primarilyto correlate the particular ticket being tested with the electricalsignature information stored in the computer. Alternatively, datarelated to the expected signal can be contained in the validation number78. In either case, the validation number provides the primary methodfor accessing the information related to the expected electricalsignature(s) of the ticket.

After the ticket 50 is coupled to the electronic verification machine108 via the ticket interface 176, the electronic verification machine108 completes the discreet verification process for each of the playspot resistor tracks 82-96, as explained above in Section IV.A. Theelectronic verification machine determines the measured electricalsignature for each of the play spot resistor tracks 82-96 and comparesthese values to the value or values stored either in the validationnumber 78 of the ticket 50 or in a look-up table in the central computer223 or the processor board 220. If the measured resistance of a specificplay spot resistor track 82-96 is substantially the same as the storedvalue of the resistance, the associated play spot area 72A-G is in itsoriginal integral state and has not been at least partially removed. If,on the other hand, the measured resistance is substantially differentthan the stored value for the resistance, the associated play spot area72A-G is treated by the electronic verification machine 108 as havingbeen removed. This occurs, for example, when the associated play spotarea has been at least partially removed by a player playing the ticketor when the ticket has been tamped with.

In this particular example, the ticket 50 is considered valid only ifthe number of play spot areas 72A-G specified in the rules 58 have beenremoved to reveal the underlying play indicia 74. For example, the rules58 for a particular game may require rubbing off only three play spotareas 72A-G. If an individual rubs off more than three play spot areas72A-G, the ticket 50 is void even if three of the revealed play indicia74 match. If the electronic verification machine 108 determines that theticket 50 is valid, that is the ticket 50 has been played according tothe rules 58, the electronic verification machine 108 then proceeds todetermine the redemption value of the ticket 50.

The electronic verification machine 108 can validate or determine theredemption value of the ticket, such as ticket 50, in either of twoways: (1) by accessing the play indicia value data stored in the barcode 80 on the ticket 50; or (2) by accessing a ticket redemption filecontained in the central computer 223 or the processor 220. Storing theplay indicia value data in the bar code 80 has the advantage ofpermitting local determination of the redemption value of the ticket 50.Consequently, any lottery terminal can determine the redemption value ofa ticket without contacting a central lottery or host computer thusreducing the cost and time required in the redemption process. On theother hand, it is not inconceivable that the play spot value code in thebar code 80 could be broken even though there are a very large number ofpotential play spot value combinations that can be printed on the ticket50. As a result there is some possibility that an individual couldpredict the winning combinations present on ticket 50 based upon the barcode 80. Maintaining a separate ticket redemption value file in thecentral computer 223 or the processor 220 will normally result inincreased ticket security because the play indicia value data are notstored in a bar code 80 on the ticket 50. Such a system, however,requires communication with the central computer 223 or the processor220 in the electronic verification machine 108 before the ticket 50 canbe redeemed. As a result, this type of redemption process, especiallywhere a remote central computer 223 is used, can be slower and morecostly than storing the play indicia value data in the bar code.

In the preferred embodiment of the invention, therefore, the method ofstoring play indicia or redemption value data in the bar code 80typically would be used only for low level prizes. The larger cashprizes would be computed by the lottery central computer 223 in order toincrease the security of the system with respect to high tier prizes orredemption values. In this embodiment, the bar code 80 would storeinformation concerning all the play indicia 74 on the ticket 50. The barcode 80 can consist of, for example, 22 digits which represent a gamenumber (2 digits), a pack number (6 digits), a check digit (1 digit), aticket number (3 digits) and a play spot code (10 digits). The gamenumber is unique to each particular lottery game. The pack numberidentifies the pack from which a particular ticket originates. The checkdigit is used to help ensure that a proper bar code read has been made.The ticket number relates the relative position of a specific ticketwithin a pack. In this example, the game number, the pack number and theticket number represent ticket identification or accounting data andnormally in themselves do not contain redemption value information.

The 10-digit play spot code includes a value portion containinginformation about the value of each of the play indicia of each of theplay spots areas. An illustration of how such a 10-digit play spot codecan be used in a probability lottery ticket 422 is provided in FIGS. 36and 37. Referring to FIG. 36, the ticket 422 has sixteen play spotsareas 424A-P each of which covers a play indicia 426A-P which are shownin FIG. 37. The ticket 422 also includes a bar code 428 and avoid-if-removed area 430 which conceals a validation number (not shown)as well as a set of printed information 432 concerning the rules forplaying the ticket 432. In the example illustrated in FIGS. 36 and 37,the rules 432 state that only six play spot areas 424A-P may be removed.The ticket 422 can be redeemed for a prize if any two of the revealedplay indicia 426A-P match. FIG. 37 illustrates the ticket 422 after allof the play spot areas 424A-P have been removed to reveal the underlyingplay indicia 426A-P.

For a ticket with 16 play spots areas, such as the ticket 422, two bitsof the value portion in the play spot code are used to store informationconcerning the value of the play indicia 426A-P for each play spot area424A-P. In this example, the values of these bit pairs are as follows:“00” signifies that the value of the play spot area cannot be checkedlocally by the electronic verification machine 108; “01” signifies thatthe value of the play indicia equals $1.00; “10” indicates that thevalue of the play indicia equals $2.00; and “11” indicates that thevalue of the play indicia equals $5.00. In other words, all play indiciathat contain the $1 symbol are represented by the bit pattern “01” playindicia that contain a $2 symbol are represented by the bit pattern“10”, and play indicia that contain the $5 symbol are represented by the“11” bit pattern. Any play indicia having a value other than $1, $2 or$5 has a corresponding bit pattern of “00”. Thus, for example, all playspots having $10, $20, $50 or $100 symbols would have corresponding bitpatterns of “00”. The bit pattern “00” indicates that the play indiciavalue for the corresponding play spot area 424A-P cannot be determinedlocally and must be determined by accessing the redemption file in thecentral computer 223. The bit patterns for all of the play indicia426A-P are strung together to form a 32-bit binary number. For example,the 32-bit binary number corresponding to the play indicia 426A-P wouldbe as follows:

11 00 00 00 00 11 00 00 00 00 11 00 00 00 00 01

This binary number then is converted to base 10 in which the 32-bitnumber is represented by 10 digits, in this case 3,224,374,273. These 10digits are encrypted to form the play spot code which forms a part ofthe bar code 428. It should be noted that the 32-bit binary number canalso be converted to numbers having other bases such as hexadecimal. Forexample, the hexadecimal value of the above 32-bit binary number wouldbe C0300C01.

The bar code reader 210 in the electronic verification machine 108 readsthe bar code 428 including the play spot code. The computer on theprocessor board 220 in the electronic verification machine 108 decryptsthe 10 digit, base 10 play spot code and then converts it to a binarynumber thereby creating a 32-bit number with a 2-bit code correspondingto each of the 16 play indicia 426A-P. The computer in the electronicverification machine 108 then compares the two-bit pattern stored in theplay spot code for each play spot area 424A-P which has been previouslydetermined by the detection circuitry of the electronic verificationmachine 108 as having been played. If two or more of the rubbed-off playspot areas have a value of “00” (i.e., “can't check locally”), theelectronic verification machine 108 can not determine locally whetherthe ticket 422 is a winner of a high tier prize and if so, theredemption value of the ticket 422. Thus, in the exemplary ticket 422illustrated in FIGS. 36 and 37, if the bit pattern for any of therevealed play indicia 426A-P matches the bit pattern for a secondrevealed play indicia 426A-P, the redemption value of the ticket 422equals the value of the matching play indicia 426A-P. For example, iftwo of the revealed play indicia 426A-P have a bit pattern equal to“11”, the redemption value of the ticket 422 is five dollars. Theelectronic verification machine 108 then informs the lottery agent ofthe redemption value of the ticket 422 via the display 180 or theprinter 181 so that the ticket 50 can be paid.

If two of the entries in the table corresponding to the rubbed-off spotsare “00”, however, the electronic verification machine 108 will not beable to locally determine the redemption value of the ticket 422. Herethe “00” bit pattern indicates that the rubbed-off play spots representa high redemption value or that there may be more than one possibleredemption value, for example, the value of all play indicia greaterthan five dollars. In this case, the electronic verification machine 108accesses the ticket redemption file in the central computer 223 todetermine the redemption value of the ticket 422. In one arrangement theredemption file in the central computer 223 contains a record or a listfor each ticket 422 in which the play indica value data are stored inassociation with a ticket identity number. The ticket identity number,for example accounting data contained in the bar code 428 or containedin a conventional validation number 78, which uniquely identifies aticket within a game is transmitted to the central computer 223 and canbe used as an address to locate the record in the redemption filecontaining the indica or redemption values for that ticket. Thus, forexample, the ticket redemption file for the ticket 422 includes playindicia value data which enables the central host computer 223 todetermine whether or not any two of the rubbed-off spots has the samesymbol (e.g., all $10, all $20, etc.). The central host computer 223then transmits a signal to the electronic verification machine 108indicating whether or not the ticket 422 is a winner, and if so, theredemption value of the ticket 422. It should be noted that thefunctions of the central computer 223 and its associated redemption fileas described above can be preformed by the computer in the processorboard 220 of the electronic verification machine 108.

As an alternative more than 2 bits can be used to represent each playspot. This will permit more or even all of the play spot areas to bevalidated by the electronic verification machine 108. This embodimentreduces or eliminates calls to the central host computer 223. However,this embodiment requires a longer play spot code and, hence, a longerbar code 428 if all the other fields in the bar code are kept at thesame size as in the previous embodiment. As indicated above, the size ofthe bar code 80 can be reduced if a play spot code having a base largerthan 10 is used.

A second approach to ticket validation involves using a validation filein the central computer 223 rather than encoding play indicia value datain the bar code 428 on the lottery ticket 422. In this embodiment, thevalidation number only contains information related to the identity ofthe ticket, for example, the game number, pack number and ticket number.The validation number is read by the electronic verification machine 108when, for example, the lottery agent inputs the validation number viathe keyboard 178 of the electronic verification machine 108.Alternatively, the validation number and game number can be stored onthe ticket in a machine-readable format, for example, as part of the barcode 428 or even as a magnetic stripe. After the electronic verificationmachine 108 determines which play spot areas have been removed, theelectronic verification machine 108 transmits the data as to which playspot areas have been removed along with the validation number to thecentral computer 223. The central computer 223 contains the redemptionor validation file which includes information corresponding to theticket identification information for each ticket as well as a recordwith play indicia value data corresponding to each of the play spotareas 424A-P on each ticket 422. The central computer 223 then uses theticket identification information to read the record corresponding tothe ticket 422 and obtains the play indicia value data corresponding tothe play spot areas 424A-P that have been removed. If the number of therubbed-off play spot areas 424-P specified in the rules 432, contain thesame symbol, the ticket is a winner. The central computer 223 thendetermines the redemption value corresponding to the matching playindicia value data and sends authorization to the electronicverification machine 108 so that the redemption value can be paid. Anadditional advantage of this approach is that after a ticket has beenpresented for redemption, the records within the validation file whichcorrespond to the ticket can be updated to reflect that the ticket hasbeen verified by the electronic verification machine 108 and the centralcomputer 223. Consequently, the ticket 422 can be presented forredemption only one time and thereafter the validation file containsinformation indicating that the ticket has been previously paid.

VI. Stigmatization

There are cases where it is desirable to provide a positive indicationthat a document such as the lottery ticket 50 has been verified orvalidated by the electronic verification machine 108. This process istermed stigmatization. One approach as described above in Section V. isto register each ticket 50 or document in a central computer that isconnected to the electronic verification machine. Another approach is tostigmatize the ticket 50 or document itself.

Providing a hole puncher in the electronic verification machine 108 isone way to accomplish this object. In this case a hole is punched thougha critical portion of the partial printed circuit after the verificationprocess has taken place.

Printing a cancellation or void indication on the document by means of aprinter such as a dot matrix printer (not shown) located in theelectronic verifications machine 108 after verification is anotherapproach that can be used.

Fuses located in the circuits printed on the document can be used tostigmatize or void the document. Here sufficient power is applied to thedocument such as the lottery ticket 50 by the electronic verificationmachine 108 to break for example one or more of the resistors 82-94 orblow selected fuses printed on the document. It should be noted thatfuses of this nature can also be used to store specified information inthe document. For example, if an array of fuses is printed on thedocument, information can be stored on the document by having theelectronic verification machine 108 selectively burn certain fuses muchas a PROM is programmed. This technique has applications other thanlottery tickets such as an alternative to magnetic stripes on creditcards. Information burned in by blowing fuses can be far more difficultto alter than information contained in a magnetic stripe.

Coloration can also be used to stigmatize the document. In this case thedocument such as the lottery ticket 50 would also be printed withtemperature sensitive ink. Power applied to the document by theelectronic verification machine 108 would generate sufficient heat inthe circuits printed on the document to change the color of at least aportion of the document.

VII. A Second Electronic verification Machine and Verification Methods

FIGS. 38 and 39 illustrate a second embodiment of the invention, whichis a second electronic verification machine 500. The basic components ofthe electronic verification machine 500 are shown in block diagram formin FIG. 40. Included in the electronic verification machine 500 is asensor array 502 which is connected to a digital processor board 504 bya set of sensor plate lines 506 and an excitation line 508. A set oflines 510-514 provides signal inputs and outputs to a microcontroller516 which forms part of the digital processor board 504. A suitablemicrocontroller 516 is the Motorola MC68HC711E9CFN2 that includes amultiplexed 8 bit analog to digital converter (“A/D”) 517. Theelectronic verification machine 500 also includes a bar code reader 518,a stepper motor mechanism 520 and a set of three document positionsensors 522 which are connected to the digital processor board 504 by aset of lines 524-528. In the embodiment of the invention shown in FIG.38, the digital processor board 504 is connected by a RS-232C serialdigital interface 530 to a commercially available, microprocessor based,lottery retail terminal 532 that includes a random access memory 534. Aset of indicator lights 535 that in this embodiment include “power on,”“ready” and “jammed ticket” also form a part of the electronicverification machine 500.

FIG. 39 is a sectioned side view of the electronic verification machine500 which is primarily provided to illustrate a document interface andtransport mechanism, indicated generally by 536. Secured to a housing538 is an upper document guide plate 540 and a lower document guideplate 542 that combine to form a channel 544 through which a document,such as a lottery ticket, can pass. The document (not shown) is placedin the upper opening 546 of the channel and drops down in response togravity until it makes contact with a first set of pinch rollers 548 and550 that extend through an aperture 552 and an aperture 554 in guideplates 540 and 542 respectively. Also included in the electronicverification machine 500 is a second set of pinch rollers 556 and 558that extend through an aperture 560 and an aperture 562 in guide plates540 and 542 respectively; a pressure roller 564 which extends through anaperture 566 in the lower guide plate 542; a set of three document edgedetectors 568, 570 and 572 that are represented in FIG. 38 as thedocument position sensors 522; and the bar code reader 518 which ismounted in an aperture 574 of the lower guide plate 542. A mirror 575 ismounted over the aperture 574 which makes it possible for the bar codereader 518 to read bar codes on either or both sides of the document asindicated by a dashed line 577. In addition, the sensor array 502 ismounted on the upper guide plate 540 opposite the pressure rolleraperture 566. The pinch rollers 550 and 558 along with the pressureroller 564 are connected to the stepper motor 520 by a toothed belt (notshown) so that the rollers 550, 558 and 564 will all rotate at the samerate.

In operation, the document (not shown) is placed in the upper opening546 of the channel and drops down in response to gravity until it makescontact with the first set of pinch rollers 548 and 550 which arenormally not rotating. Meanwhile, the first edge detector 568 willprovide an indication to the microcontroller 516 that a document ispresent in the channel formed by the guide plates 540 and 542 causingthe stepper motor 520, in response to a first pulse rate applied to thestepper motor 520 by the microcontroller 516, to rotate at a first rate.When the document has been detected by the second edge detector 570 asemerging from the pinch rollers 550 and 548, the microcontroller 516will increase the rate of rotation of the stepper motor 520 resulting inthe document being transported by the rollers 550, 564 and 558 at a rateof approximately 8 inches per second past the sensor array 502. Thesecond edge detector 570 also provides the mircrocontroller 516 with theprecise location of the document so that the microcontroller 516 caninitiate scanning of the document. The pinch rollers 548, 550, 556 and558 are composed of a conventional elastomeric material and the pressureroller 564 is preferably composed of a closed cell polyurethane materialin order to prevent this roller from absorbing or retaining any moisturethat might be on the document. The purpose of the pressure roller 564 isto insure contact between the document and the sensor array 502. Afterpassing the sensor array 502, the document will pass the bar code reader518, which will transmit the bar code information on the document to themicrocontroller 516, and the edge detector 572 will provide anindication to the microcontroller 516 that the document has exited theelectronic verification machine 500.

It should be noted that the configuration of the electronic verificationmachine 500 shown in FIG. 39 has a number of significant advantagesincluding: a straight document path that minimizes the possibility ofpaper jams; positive control of the document by the stepper motor 520 inconjunction with the pinch rollers 550 and 558; the use of the pressureroller 564 to maintain contact of the document with the sensor array502; and the use of the edge detectors 568-572 to provide themicrocontroller 516 with information as to the location of the documentin the electronic verification machine transport mechanism 536. Inaddition, a self cleaning effect occurs because the document is inmoving contact with the sensor array 502 and further more, theelectronic verification machine 500 can readily accept documents ofvarying thickness.

FIG. 40 is a block diagram illustrating in more detail portions of thepreferred embodiment of the sensor array 502, the digital processorboard 504 and the microcontroller 516 of FIG. 38. In this embodiment ofthe invention, the sensor array includes 14 sensor plates, designated byreference numeral 574, and a rectangular excitation plate 576 mounted ona printed circuit board 578. A set of 14 operational amplifiers,designated by reference numeral 580, have their inverting inputsconnected by the lines 506 to each one of the sensor plates 574. Alsoconnected to the inverting inputs and the outputs of the operationalamplifiers 580 is a feedback line, indicated by reference numeral 582,that includes a feedback resistor R_(f). The noninverting inputs of theoperational amplifiers 580 are connected to ground as shown by lines584. The outputs of each of the operational amplifiers 580 are connectedto one of two multiplexers 586 or 588 that in turn are connected by apair of lines 590 and 592 to a pair of precision rectifiers 594 and 596.The rectifiers 594 and 596 are connected to the analog to the digitalinput 517 of the microcontroller 516 via the lines 510 and 512. Controlis provided to the multiplexers 586 and 588 from the microcontroller 516by the line 514. In addition, the circuit of FIG. 40 includes a trianglewave voltage generator 598 that applies an AC excitation voltage overthe line 508 to the excitation plate 576. The voltage generator 598 canbe controlled, in this case switched on or off, by the microcontroller516 over a line 600. For illustrative purposes, FIG. 40 also includeswithin a dashed line 602 an equivalent circuit of a document under testwhere C_(t1) represents the capacitance between the excitation plate 576and the document; R_(t) represents the resistance in the documentbetween the excitation plate 576 and the first sensor plate 574; andC_(t2) represents the capacitance between the document and the firstsensor plate 574.

One of the objects of the circuit shown in FIG. 40 is to scan thedocument under test 602, such as a lottery ticket, for conductivematerial. Because the frequency and amplitude of the voltage generatedby the triangular waveform voltage generator 598 are constant, thecurrent I on the sensor plate 574 will be a square wave due to therelation I=C_(total) dv/dt where C_(total) is the combined capacitancesof C_(t1) and C_(t2). As a result the voltage drop across the feedbackresistor R_(f) will be a square wave having its amplitude proportionalto the capacitance C_(total). The preferred frequency of the voltagegenerator is between 20 KHz and 150 KHz. Thus, the voltage output onlines 582 of the operational amplifiers 580 can be used to determineboth the value of the coupling capacitance C_(total) and if there isconductive material between each of the sensor plates 574 and theexcitation plate 576. By using two multiplexers 586 and 588 and therectifiers 510 and 512, the microcontroller 516 can, in effect, samplethe current on each of the sensor plates 574, which would result fromconductive material on the document 602, thereby providing an indicationof the presence or absence of conductive material across the document602. The stepper motor 520 of the electronic verification machine 500advances the document 602 in discrete steps of approximately between0.02 inches and 0.03 inches past the sensor array 502 and themicrocontroller 516 applies the excitation signal to the excitationplate 576 for each step. In this manner the microcontroller 516 can beprogrammed to scan a predetermined portion or even the whole document602 for conductive material as well as the values of the couplingcapacitance C_(total).

Another very important capability of the circuit shown in FIG. 40, inaddition to the determination of the presence of conductive material onthe document under test, is that it can be used to determine anelectrical signature of the document. For example, the electricalsignature representing an electrical characteristic such as resistancecan be measured as is discussed in more detail in connection with thecircuits of FIGS. 18 and 41. Also, a measure of the total couplingcapacitance C_(total) can be used as an electrical signature. Asindicated above, if the voltage generator 598 generates a constantfrequency triangular wave form, the current I on the sensor plate 574will be linearly related to the capacitance C_(total) and therefore thecoupling capacitance C_(total) itself can be measured. The totalcapacitance C_(total) depends on the characteristics of the documentunder test, such as the dielectric constant K of a dielectric materialcovering the conductive material or the thickness t of the dielectricmaterial, while other factors including the size of the excitation plate576 and the sensor plates 574 remain essentially constant. As a result,the value of the current I or changes in the current I can be used tomeasure a capacitive electrical signature of the document. For example,it would be possible in some cases to use a capacitive electricalsignature to determine if a scratch-off coating covering conductivematerial on a lottery ticket has been removed.

In the embodiment of the sensor array shown in FIG. 40, the 14 sensorplates 574 are square with each side 0.10 inches in length and theexcitation plate is 0.10 inches in width. The excitation plate 576extends parallel to the linear array of sensor plates 574 and is locatedabout 0.050 inches from the sensor plates 574. Improved control ofcapacitance coupling is provided for by utilizing the pressure roller564 of FIG. 39 to maintain the document 602 in direct physical contactwith the sensor array 502. Also, to insure adequate values ofcapacitance between the document 602 and the plates 574 and 576, asrepresented by the capacitors C_(t1) and C_(t2), the metal sensor andexcitation plates 574 and 576 are coated with a material having adielectric constant greater than 5. A suitable material for this coatingis Kapton. In the event that a document interface is used where thedocument is not in contact with the sensor or excitation plates, ispreferable that an air gap of less than 0.004 inches be maintainedbetween the document and the plates. Also, in order to assure adequatevalues of sensed capacitance, it is preferable to have the rectangularexcitation plate 576 several times larger in area than the sensor plates574.

It should be noted that one of the advantages of the verification orvalidation method described above, is that the ticket or document can beprinted on a flexible substrate such as paper and because the conductivematerial can be in direct contact with the sensor array 502, it is notnecessary to apply a dielectric material over the document.

Illustrated in FIG. 41 is an alternate embodiment of a sensor circuit ofthe type shown in FIG. 18 that can be used to make measurements of theelectrical signatures, such as resistance, of conductive material ondocuments. The circuit of FIG. 41 is suitable for use with themechanical arrangement of the electronic verification machine 500 shownin FIG. 39 and is generally equivalent in function to the sensor array502 and the processor circuits 504 shown in FIGS. 38 and 40. Forpurposes of explanation, the circuit diagram of FIG. 41 includes thedocument under test equivalent circuit 602 which has been described inconnection with FIG. 40 and the equivalent elements from FIGS. 18, 38and 40 carry the same reference numbers. As with the circuit of FIG. 18,an inductor 604, for example having an inductance of 100 mH, isconnected to each of a set of 5 sensor plates 606 in order tocompensate, in phase, for the reactance resulting from the capacitancebetween the document 602 and the sensor plates 606 and a correspondingset of excitation plates 608. The microcontroller 516 can be programmedto perform the same frequency sweeping functions as the mircrocontroller224 described in connection with FIG. 18 and the processor circuits 504can contain functional elements equivalent to the integrator (peakdetector) 238, the D/A converter 240 and the VCO 242. Included in thiscircuit is a set of 5 excitation plates 608. Although not shown in theschematic diagram of FIG. 41, the excitation plates 608 can be locatedbetween and aligned in a linear array with the sensor plates 606.Although a single excitation plate 576 of the type shown in FIG. 40 canbe used instead of the separate excitation plates 608, the use ofseparate excitation plates 608 in this embodiment of the invention hasthe advantage of reducing distributed capacitances. Connected to each ofthe excitation plates 608 by a line 609 is a triangular wave voltagecontrolled oscillator (VCO) 610 in order to apply a triangularly shaped,AC excitation voltage or signal to the document under test. However, itshould be noted that optimal performance of a resonant circuit can beachieved with a sinusoidal wave form instead of the triangular wavevoltage generated by the generally less expensive VCO 610. Also includedin this circuit is a set of 5 operational amplifiers 612 connected in avoltage follower arrangement with the sensor plates 606. Specifically,the noninverting inputs of each of the operational amplifiers 612 areconnected, in this case, through the inductors 604 to the sensor plates606 and to a resistor 614 that in turn is connected to ground. As aresult, the output of each of the operational amplifiers 612, on a setof lines 616 which are also connected to the inverting input of theoperational amplifiers 612, will be a voltage that represents thecurrent flow through the resistor or resistance R_(t) of the document602 resulting from the excitation signal on line 609.

As indicated above, the circuit of FIG. 41 can use a control circuit618, which can include a microcontroller such as the microcontroller516, to perform an iterative resonance seeking algorithm to vary thefrequency of the VCO 610 until the resonance of the LC circuit includingthe inductor 604 and the capacitance between plates 606 and 608 isfound. The resulting voltage on lines 616, which can be multiplexed,peak-detected and applied to the analog to digital input 517 of themicrocontroller 516 in a manner similar to that shown in FIG. 40,represents the value of the resistance of a conductive material on adocument. In this way it is possible to determine the electricalsignature, for example the value of resistance, of conductive materiallocated in a predetermined position on a document. Since it is possibleto make accurate measurements of electrical signatures using the circuitof FIG. 41, this approach can be particularly useful for thosedocuments, such as a lottery probability ticket of the type shown at 50in FIG. 1, where particular accuracy may be important. Also, once thecontrol circuit 618 has determined the resonance frequency, it can use astandard resonance frequency equation, such as C=25,330/f² L, todetermine the coupling capacitance to the document since the inductanceof the inductor 604 is known.

Another embodiment of a sensor array is illustrated in FIG. 42 where adocument 620, such as a lottery ticket, is inserted between an upperarray of sensor plates 622 and a lower array of excitation plates 624.This arrangement has the advantage of reducing the sensitivity of thesystem to displacement of the document 620 in a direction perpendicularto the plane of the document 620.

As illustrated in FIGS. 43-45, one of the advantages of the systemsshown in FIGS. 38-40 is that it is possible to determine the location aswell as the shape of conductive material on a document. As an example ofhow shapes on a document can be determined, a conventional instantlottery ticket 626 having a scratch-off coating 628, shown partiallybroken away, covering a set of play indicia 630 is illustrated in FIG.43. In this case the scratch-off coating includes a conductive materialand one object of the system in this example is to determine whatportion of the scratch-off coating has been removed as part of a ticketvalidating process. Contained in the terminal memory 534, shown in FIG.38, is a game signature map 632 in which a bit map or digitalrepresentation of the shape of the scratch-off coating 628 of the ticket626 is stored. As previously described in connection with FIGS. 38-40,the electronic verification machine 500 scans the ticket 626 forconductive material and the microcontroller 616 then transmits a digitalrepresentation of the location of the conductive material detected onthe ticket 626 to a scanned data map contained in the memory 534. Atthis point a microprocessor (not shown) in the lottery terminal 532 cancompare the contents of the scanned data map 634 to the game signaturemap and if the data in the scanned data map meets certain predeterminedcriteria such as location, shape or percentage of expected removal ofthe scratch-off coating 628, then a comparison signal is generatedindicating that the ticket 626 has passed a verification or validationtest. One method for representing verification criteria is by a vector.In the case of the ticket 626, such a vector might have several bytesrepresenting the starting address and the ending address of the gamesignature map 632 corresponding to where the scratch-off coating 628 canbe expected along with another byte having a value that represents theminimum percentage of the scratch-off coating that constitutes anacceptably played ticket. As a practical matter, players often onlyscratch off a portion of the lottery ticket's scratch-off coating, sothat, for example, an acceptable percentage for a particular type ofplayed ticket might be 30%. Use of vectors of this type makes itespecially easy to reprogram the terminal 532 for different types oflottery tickets or documents.

Another method of verifying a document such as a lottery ticket of thescratch-off type 626 is to utilize the capacitive signature of theticket 626 as measured by the electronic verification machine 500.Taking, for example, the ticket 626 which can include a uniformconductive material (not shown) applied beneath the scratch-off coating628 and that is removable with the coating 628 of the type as describedin U.S. Pat. No. 5,346,258, a measure of the signal to noise ratiobetween areas of the ticket 626 having the scratch-off coating 628 andthe areas that do not, can provide a strong indication of validity. Thismethod starts by determining a value for the coupling capacitanceC_(total) for each location on the ticket 626 by measuring the current Ion the sensor plates 574 using the circuit of FIG. 40. Then by takingthe mean average T_(s) of the value of the coupling capacitance of theareas of the ticket 626 having the scratch-off coating 628 along withthe mean average T_(p) of the other areas and dividing T_(s) by T_(p), asignal to noise ratio can be obtained. Here, T_(s) represents the signaland T_(p) represents the noise. Preferably, the value of T_(s) iscalculated from only those coupling capacitance values that exceed apredetermined value such as 11 out of a maximum sensed value of 36.Computing this signal to noise ratio for an entire document such as theticket 626 can provide an excellent indication of the validity of thedocument. It has been found, for instance, that lottery tickets of thetype 626 will consistently produce signal to noise ratios of between 3.6and 4.9.

One of the reasons that the above described signal to noise ratios canprovide such an excellent indication of validity is that it measures aninherent electrical signature of a document that can be very difficultto forge. In the example above, the measured coupling capacitanceC_(total) of the scratch-off areas 628 of the ticket 626 are a functionof two independent factors: the thickness t and the dielectric constantK of the scratch-off coating 628. Because C_(total) is equal toK∈_(o)A/t where ∈_(o) is the permittivity of free space and A is thearea of the capacitor plate 574, a forger would have to almost exactlymatch both the thickness t and the dielectric constant K of thescratch-off coating.

In addition to lottery tickets, the scanning method as described abovecan be useful in the verification of a wide variety of documents. Forinstance, currency bills can be printed with conductive fibers orconductive inks located in predetermined locations. The electronicverification machine 500 can then be used to verify the authenticity ofthe bills by determining electrical signatures as well as the locationor the amount of conductive material in the bills. Since the electronicverification machine 500 of FIGS. 38-40 can operate at relatively highspeed, 8 to 10 inches per second, the verification of documents can beaccomplished quickly and inexpensively.

Another application for the electronic verification machine 500 is inthe validation of a pull-tab type lottery ticket 636 as shown in FIG.46. The pull-tab ticket 636 is made up of a substrate 638 upon whichplay indicia, indicated by 640, are printed. Laminated over thesubstrate 638 is a pull-tab stock member 642 having a number ofperforated pull-tabs 644 located such that they cover the play indicia640. The underside or laminate surface of the pull-tab member 642 isprinted with a layer of conductive ink, as indicated by referencenumeral 646, which forms a conductive plane and is not obvious to aplayer. In this type of ticket 636, the conductive plane formed by theconductive ink layer 646 will be interrupted when a player removes oneor more of the pull-tabs 644.

Referring to FIG. 47, a pull-tab signature map 648 is graphicallyrepresented along side the pull-tab ticket 636, with pull-tabs 644 shownas removed. As shown in this figure, the “0” bits in the signature map648 correspond to positions of the pull-tab 644 on the ticket 638. Theremaining bits in the signature map 648 are set to “1.” As a result, thesignature map 648 provides a digital representation of the location ofthe pull-tabs 644 along the center line of the pull-tab ticket 636. Thesignature map 644 can be stored in the memory 534 of the lotteryterminal 532 or in the case where a simplified version of the type ofelectronic verification machine 500 of FIG. 38 is to be used, thesignature map 644 can be stored in the microcontroller memory 516 or itsequivalent.

A simplified sensor array 650, which can be used in the electronicverification machine 500 to validate the pull-tab ticket 636, is shownin FIG. 48 as positioned over the pull-tab ticket 636. The sensor array650 includes a sensor plate 652 located between a pair of excitationplates 654 and 656 such that the sensor plate 652 is aligned with thecenter line of the pull-tab ticket 636. The circuits (not shown)connected to the sensor and excitation plates 652 and 654 aresubstantially the same and operate in the same manner as the circuits inFIG. 40. In validating the pull-tab ticket 636, the ticket 636 isscanned along its center line, in the direction indicated by an arrow656, by the sensor plate 652 and its associated circuity in theelectronic verification machine 500. If, for example, the output ofsensor plate 652 is equivalent all “0”s, then the ticket 636 does notcontain conductive ink and, as such, can be considered a forgery,perhaps a photocopy. Then by comparing the sensor plate 652 output tothe signature map 644 it is possible to determine how many, if any, ofthe pull-tabs 644 have been opened.

VIII. A Second Probability Game Ticket Configuration

FIGS. 49-50 and 52-72 show a second embodiment of a probability gameticket 700, which is the preferred embodiment to be used in conjunctionwith the sensor array 502 of the electronic verification machine 500,shown in FIGS. 38-40. FIG. 49 presents the finished appearance of theticket 700. The ticket 700 is printed on a substrate 702, such as cardstock or paper, and has three portions: a display graphics portion,shown generally at 704, a play field portion, shown generally at 706,and a ticket identification portion, shown generally at 708. As with theprevious ticket 50, the display graphics portion 704 includes a varietyof printed information such as the name 710 of the game, rules 712 forplaying the game, and customized art work 714. The play field portion706 includes a group of play spot areas 716A-H which are printed asoverprint layers. The play field portion 706 can also include play spotgraphics 718 which help to further visually delineate each play spotarea 716A-H. Each play spot area 716A-H conceals a play indicia 720A-H(shown in FIG. 61). For example, play spot area 716A has been removed toreveal the underlying play indicia 720A. The ticket identificationportion 708 includes a void-if-removed area 722 which is printed as anoverprint layer. The void-if-removed area 722 can include overprintgraphics 724. The void-if-removed area 722 conceals a validation number726 (shown in FIG. 61) which contains information that can be used invalidating the ticket 700. The ticket identification portion 708 alsoincludes an inventory control number 728 and a machine-readable bar code730. Similar to the bar code 80 of the first ticket 50, the bar code 730can include information related to the validation number 726 (shown inFIG. 61), to the pack and ticket numbers for the ticket 700 and to theredemption values of the play indicia 720A-H. The bar code 730 thusserves as a ticket identification indicia for the ticket 700.

FIG. 50 is a plan view of various circuit elements which are used indetermining the authenticity and integrity of the ticket 700. The ticket700 includes two general types of circuit elements which are used inassociation with the play indicia 720A-H and with the bar code 730. Thefirst type of circuit element consists of individual indicia circuitelements 732A-H which are used to determine the presence of the playindicia 720A-H as well as the integrity of each of the underlying playindicia 720A-H. Each of the indicia circuits 732A-H includes a firstcapacitive pick-up area, generally denoted as 734, a second capacitivepick-up area, generally denoted as 736, and a resistive element,generally denoted as 738, that is connected to and extends between thefirst and second capacitive pick-up areas 734 and 736. Thus, forexample, the indicia circuit element 732A includes the first capacitivepick-up area 734A, the second capacitive pick-up area 736A and theresistive element 738A. Similarly, the indicia circuit element 732Bincludes the first capacitive pick-up area 734B, the second capacitivepick-up area 736B, and the resistive element 738B. The resistiveelements 738A-H are printed in a serpentine pattern so as to cover mostof the play indicia 720A-H. As explained in more detail with referenceto FIGS. 69-70, each of the indicia circuit elements 732A-H isassociated with one of the underlying play indicia 720A-H. Thus, forexample, the indicia circuit element 732A is associated with the playindicia 720A, shown in FIG. 1. The individual indicia circuit elements732A-H are printed on the ticket 700 so that at least a portion of eachindicia circuit 732A-H overlies one of the individual play indicia720A-H. In the preferred embodiment, the resistive element 738 of theindicia circuit elements 732 are printed on the ticket 700 to overlieone of the play indicia 720. Moreover, in the preferred embodiment thecapacitive pick-up areas 734 and 736 of the indicia circuit elements 732are printed on the ticket 700 so that the capacitive pick-up areas 734and 736 do not overlie any of the play indicia 720. Thus, for example,the resistive element 738A of the indicia circuit element 732A isprinted in the ticket 700 to overlie the play indicia 720A and while thecapacitive pick-up areas 734A and 736A of the indicia circuit element732A are printed on the ticket 700 so that the capacitive pick-up areas734A and 736A are spaced-apart from the play indicia 720A and do notoverlie the play indicia 720A or any of the other play indicia 720B-H.

The individual indicia circuit elements 732A-H capacitively couple withthe sensor array 502 of the electronic verification machine 500 when theticket 700 is placed in the opening 546 of the electronic verificationmachine 500 and is moved through the electronic verification machine bythe stepper motor 520, the pinch rollers 548, 550, 556, 558, and thepressure roller 564, as described with reference to FIGS. 38-40.Specifically, the first capacitive pick-up areas 734A-H capacitivelycouple with the sensor plates 574 of the sensor array 502 and thereforeserve as sensor capacitive pick-up areas for the indicia circuitelements 732A-H. In addition, and the second capacitive pick-up areas736A-H capacitively couple with the excitation plate 576 of the sensorarray 502 and therefore serve as excitation capacitive pick-up areas forthe indicia circuit elements 732A-H. Consequently, the dimensions andpositions of the capacitive pick-up areas 734A-H and 736A-H aredetermined by the dimensions and positions of the excitation plate 576and the sensor plates 574 of the sensor array 502. In the preferredembodiment, the width of both the first and second capacitive pick-upareas 734A-H and 736A-H is on the order of 0.26 inches, the height ofthe first capacitive pick-up areas 734A-H is about 0.05 inches, and theheight of the second capacitive pick-up areas 736A-H is on the order of0.10 inches. In addition, the first capacitive pick-up areas 734A-H arelongitudinally spaced-apart from the second capacitive pick-up areas736A-H by a predetermined distance which, in the preferred embodiment isabout 0.07 inches. Moreover, each of the individual indicia circuitelements, for example, indicia circuit element 734B, is longitudinallyspaced apart from adjacent indicia circuit elements, for example,indicia circuit elements 732A and 732C, by a predetermined distance. Theconfiguration of the indicia circuit elements 732A-H offer severaladvantages. First, the individual indicia circuit elements 732A-Hprovide discreet electrical signatures for each of the play spot areas716A-H and associated underlying play indicia 720A-H. Consequently, theindicia circuit elements 732A-H can be used to determine the presence aswell as the integrity of the individual play spot areas 716A-H and theassociated underlying play indicia 720A-H. In addition, each of theindicia circuit elements 732A-H is spatially isolated from other circuitelements. Consequently, stray electrical noise is minimized oreliminated.

As explained in more detail below, portions of the indicia circuitelements 732A-H are removed when the play spot areas 716A-H are removedto reveal the play indicia 720A-H. Consequently, the ink used to printthe indicia circuit elements 732A-H should have a reduced adhesivenessso that the portions of the indicia circuit elements 732A-H are readilyremoved from the ticket 700. In addition, the ink used to print theindicia circuit elements 732A-H should also be fairly conductive. In thepreferred embodiment, the sheet resistivity of the ink used to print theindicia circuit elements is about 8 MΩ/□. A suitable formulation for anink which can be used to print the indicia circuit elements 732A-H isgiven in Table 4.

TABLE 4 Ink Formulation For The Indicia Circuit Elements 732A-H materialwt % water 41.8% Dispersant (W-22) 4.8% Dimethylethanolamine 0.25%Defoamer (RS-576) 0.4% Carbon Black 15% wetting agent (BYK 348) 0.5%EVCL Emulsion Vancryl 600 3% Ammonium Hydroxide 0.25% DC-24 SiliconeEmulsion 2% Styrenated Acrylic Varnish (J678) 5% Plasticizer 141 2%Styrenated Acrylic Emulsion 7830 20% Ethanol 5%

The second general type of circuit element is an integrity circuitelement 740 that is used to determine the authenticity and integrity ofthe ticket identification indicia, such as the bar code 730. Theintegrity circuit element 740 includes a first capacitive pick-up area742 that is shaped and sized to capacitively couple with one of thesensor plates 574 of the sensor array 502. The integrity circuit element740 also includes a second capacitive pick-up area 744 that is shapedand positioned to capacitively couple with the excitation plate 576 ofthe sensor array 502. Both the first and second capacitive pick-up areas742 and 744 are printed entirely within the ticket identificationportion 708 of the ticket 700 and, as explained in more detail below,underlie at least a portion of the ticket identification indicia, suchas the bar code 730. The ticket integrity circuit 740 also includes aresistive element 746 that is connected to and extends between the firstand second capacitive pick-up areas 742 and 744. The resistive element746 is printed on the ticket 700 so that a portion 748 of the resistiveelement 746 is located within the play field portion 706 of the ticket700 and is shown as encompassing indicia circuit elements 732D and 732H.The integrity circuit element 740 provides a discreet electricalsignature for the ticket identification indicia, such as the bar code730, and thus can be used to determine the authenticity and integrity ofthe ticket identification indicia. For example, if an attempt is made toreplace the bar code 730 by cutting the ticket 700, the resistiveelement 746 would also be cut and thus detectable by the electronicverification machine 500.

The ticket 700 can include additional data circuits, generally denotedas 750, which can be used to provide additional ticket authenticity andintegrity information. The data circuits 750 include first capacitivepick-up areas 752 and second capacitive pick-up areas 754 that arepositioned and shaped to capacitively couple with one of the sensorplates 574 and with the excitation plate 576, respectively, of thesensor array 502. The data circuits 750 also include data tracks 756that spans between the capacitive pick-up areas 752 and 754. The datatracks 756 are used to electrically store data in a binary form. Forexample, when the data tracks 756 include a conductive material the datatracks can encode a bit-on or “1” signal. Alternatively, when the datatracks 756 do not include a conductive material the data tracks 756 canencode a bit-off or “0” signal. As shown in FIG. 50, the ticket 700preferably includes at least two data circuits, 750A and 750B, both ofwhich are printed within the ticket identification portion 708. Byincluding two data circuits 750A and 750B, the ticket can store fourseparate binary codes, e.g., 11, 10, 01, and 00. As shown in FIG. 50,the data track 756A of the data circuit 750A does not include aconductive material and so encodes a bit-off or “0” signal while thedata track 756B of the data circuit 750B includes conductive materialand so encodes a bit-on or “1” signal. The binary code produced by thedata circuits 750A and 750B, when used in conjunction with additionalinformation stored elsewhere on the ticket 700, for example, in thevalidation number 726, can provide at least partial ticket authenticityand integrity information. The ink used to print the integrity circuitelement 740 and the data circuit elements 750A-B should be fairlyconductive. In the preferred embodiment, the ink used to print theintegrity circuit element 740 and the data circuit elements 750A-B has asheet resistivity of about 3 MΩ/□. A suitable ink for printing theintegrity circuit element 740 and the data circuit elements 750A-B wasgiven previously in Table 1.

It should be noted that the two general types of circuit elements, theindicia circuit elements 732A-H and the integrity circuit element 740,are actually printed on the ticket 700 as separate layers. In addition,the ticket 700 includes several other layers that are used to generatethe finished form of the ticket 700 shown in FIG. 49. FIGS. 51-72illustrate the sequence and configurations of the layers which formparts of the ticket 700. The ticket 700 is preferably printed by anintaglio method. A gravure printing method is especially preferred as itallows for the widest range of ink and coating formulations, althoughother intaglio printing methods can be used. The ticket 700 can also beprinted by screen printing, relief printing, planographic printing,letterpress, and flexographic printing. However, as noted a gravureprinting process is preferred for printing the ticket 700. FIG. 51presents a schematic diagram of a gravure printing press 760 which issuitable for printing the ticket 700. The press 760 has fifteen printingstations 762-790, each of which prints one layer on the ticket 700, andone ink jet printer 792 that prints the play indicia 720A-H, thevalidation number 726, the inventory control number 728, and the barcode 730. The first print station 762 prints a first layer 794 on theticket 700. The first layer 794 is an opaque blocking layer that helpsto protect the play indica 720A-H and the circuit elements 732A-H, 740,750A, and 750B, from surreptitious detection by candling.

In order that the circuit elements such as 732A-H, 740, 750A or 750B canbe detected, the first opaque blocking layer 794, as well as any otherlayer on the ticket, should be relatively non-conductive as compared tothe conductivity of the circuit elements 732A-H, 740, 750A or 750B.Otherwise, the layer 794 would tend to interfere with the detection ofthe electrical signatures of the circuit elements 732A-H, 740, 750A or750B. This is especially the case with the capacitive pick-up areas suchas 734A-H and 736A-H and in particular with respect to the capacitivepick-up areas 734A-H that serve in this embodiment as sensor capacitivepick-up areas. It has been found that a relatively conductive layerunder the capacitive pick-up area 734 can result in a noise spike,making it difficult for the electronic verification machine 500 toaccurately the presence or signature of the resistive element 738.Although it is possible to detect the presence of the resistive elements738A-H and 746 using an electronic verification machine of the typeshown at 500 where the conductivity of the circuit elements such as732A-H, 740, 750A and 750B is only twice the conductivity of an adjacentlayer such as the lower blocking layer 794, it is desirable that thedifference in conductivity be at least one order of magnitude or 10 dBand more preferably, two to three orders of magnitude or 20 to 30 dB.Therefore, it is considered preferable that, in order to reduce thesignal to noise ratio in scanning the circuit elements such as 732A-H,740, 750A and 750B, that the layer 794 appear to be substantiallynonconductive in comparison to the circuit elements 732A-H, 740, 750Aand 750B. By increasing the difference in conductivity between thecircuit elements such as 732A-H, 740, 750A and 750B and the layer 794 itis possible to reduce the manufacturing tolerances of both theelectronic verification machine 500 and the ticket 700. Thisconsideration is significant when documents and verification machinesare being produce in large volumes. In particular where the lotterytickets 700 are printed in the millions and are subject to various typesof abuse such as bending and crumpling, the difference in conductivitybetween the circuit elements 732A-H, 740, 750A and 750B and the layer794 is preferably two orders of magnitude or 20 dB. Thus, in thepreferred embodiments of the electronic verification machine 500 and theticket 700, where the blocking layer 794 is a continuous layerunderlying all of the circuit elements 732A-H, 740, 750A and 750B, thedesired relationship between the sheet resistivity (ρ_((LBL))) of thelower blocking layer 794 and the sheet resistivity (ρs_((CE))) of thecircuit elements 732A-H, 740, 750A, and 750B is at least two orders ofmagnitude as illustrated by the equation:

ρS _((LBL))≧100ρS _((CE))

FIG. 52 illustrates the preferred embodiment of the lower blocking layer794 when the lower blocking layer 794 has a sheet resistivity that is atleast one hundred times greater than the sheet resistivities of thecircuit elements 732A-H, 740, 750A, and 750B. In this embodiment, thelower blocking layer 794 is printed as a continuous, substantiallyopaque layer 796 that completely overlies the play field portion 706 andthe ticket identification portion 708 of the ticket 700. The lowerblocking layer 794 can, however, be printed with materials that have alesser difference in conductivity relative to the circuit elements732A-H, 740, 750A, and 750B as long as the configuration of the lowerblocking layer 794 electrically isolates at least portions of thecircuit elements 732A-H, 740, 750A, and 750B from the lower blockinglayer 794. For example, FIG. 53 illustrates an alternative configurationof the lower blocking layer 794 which is printed as a barred layer 798that includes laterally spaced-apart strips 800A and 800B which areprinted with a material which is minimally conductive relative to thematerial used to print the circuit elements 732A-H, 740, 750A, and 750B.The spaced-apart strips 800A and 800B are substantially opaque andlongitudinally span the play field portion 706 and the ticketidentification portion 708 of the ticket 700. The spaced-apart strips800A and 800B define channels 802A and 802B for the resistive elements738A-H of the indicia circuit elements 732A-H. The space between thestrip 800A and the interface 804 between the play field portion 706 andthe display portion 704 and the space between the strips 800A and 800Bdefine channels 806A and 806B for the capacitive pick-up areas 734A-Hand 736A-H of the indicia circuit elements 732A-H, for the capacitivepick-up areas 742 and 744 of the integrity circuit element 740, and forthe capacitive pick-up areas 752A-B and 754A-B of the data circuits750A-B. The configuration of the lower blocking layer 794 thuselectrically isolates the capacitive pick-up areas 734A-H, 736A-H, 742,744, 752A-B, and 754A-B of the various circuit elements 732A-H, 740,750A, and 750B from the minimally conductive strips 800A and 800B. FIG.54 illustrates another embodiment of the lower blocking layer 794 whichincludes a patterned layer 808 that is printed with a material that isminimally conductive relative to the circuit elements 732A-H, 740, 750A,and 750B. The patterned layer 808, which is substantially opaque, spansboth the play field and ticket integrity portions 706 and 708 of theticket 700 and defines several apertures 810A-H, 812, 814A, and 814Bwhich electrically isolate portions of the circuit elements 732A-H, 740,750A, and 750B. Specifically, the apertures 810A-H are positioned andshaped to electrically isolate the first capacitive pick-up areas 734A-Hof the indicia circuit elements 732A-H, the aperture 812 is positionedand shaped to electrically isolate the first capacitive pick-up 742 ofthe ticket integrity circuit 740, and the apertures 814A and 814B arepositioned and shaped to electrically isolate the first capacitivepick-up areas 752A and 752B of the data circuits 670A-B. As previouslynoted, the first capacitive pick-up areas 734A-H, 742, and 752A-B servea sensor capacitive pick-up areas when the ticket 700 is read by theelectronic verification machine 500. A suitable ink for printing thelower blocking layer 794 either as the barred layer 798 or as thepatterned layer 808 is given in Table 5.

TABLE 5 Ink Formulation For The Lower Blocking Layer 794 Material wt %Predesol Carbon Black 1649V 25% (KVK USA, Inc.) VCMA 10% methyl-ethylketone 65%

It should be noted that since one of the functions of the lower blockinglayer 794 is to obscure the play indicia 720A-H and the circuit elements732A-H, 740, and 750A-B, it is desirable that the blocking layer 794 bea opaque as possible. One way to achieving a sufficiently opaque layeris to use inks that contain black pigments or other dark pigments inorder to mask the circuit elements circuit elements 732A-H, 740, and750A-B. Thus, it is convenient to use carbon or carbon black in the inkused for the layer 794. Using carbon black normally will result in anink with a sheet resistivity less than would be the case with abasically non-conductive material such as the paper substrate 702.However, the ink formulation presented in Table 4 above does provide arelatively high sheet resistivity which, in this case, is greater than20 MΩ/□. Thus, as noted above, this ink formulation is suitable forprinting the lower blocking layer 794 provided at least portions of thecircuit elements 732A-H, 740, 750A, and 750B are electrically isolatedfrom the layer 794, for example, by printing the lower blocking layer794 as the barred layer 798 having spaced-apart strips 800A-B or byprinting the lower blocking layer 794 as the patterned layer 808 havingthe apertures 810A-H, 812, 814A, and 814B.

The second printing press station 764 prints the second layer 826 whichconsists of the ticket integrity circuit 740 and the data circuits750A-B. The appearance of the ticket 700 at this point depends on theform of the lower blocking layer 794. FIG. 55 shows the ticket 700 whenthe lower blocking layer 794 is printed as the continuous, substantiallynon-conductive layer 796. Both of the data circuits 750A and 750B areprinted over the first layer 796 within the ticket identificationportion 708 of the ticket 700. The first capacitive pick-up area 742 andthe second capacitive pick-up area 744 of the integrity circuit element740 are also printed within the ticket identification portion 708 overthe layer 796. The resistive element 746, which is connected to andextends between the capacitive pick-up areas 742 and 744 of theintegrity circuit element 740, is printed on the layer 796 so that theportion 748 of the resistive element 746 is located within the playfield portion 706 of the ticket 700. FIG. 56 shows the ticket 700 whenthe lower blocking layer 794 is printed as the barred layer 798. Thefirst capacitive pick-up area 742 of the integrity circuit element 740is printed in the ticket identification portion 708 and is locatedwithin the channel 806A. The first capacitive pick-up area 742 thus isnot printed over either of the strips 802A or 802B and is actuallyprinted on the substrate 702 of the ticket 700. Similarly, thecapacitive pick-up areas 752A and 754A of the data circuit element 750Aand the capacitive pick-up areas 752B and 754B of the data circuitelement 750B are printed in the ticket identification portion 708 andare located within the channel 806B. The capacitive pick-up areas 752A,754A, 752B, and 754B of the data circuit elements 750A and 750B are thusprinted on the substrate 702 of the ticket 700. Consequently, becausethe capacitive pick-up areas 742, 752A, 754A, 752B, and 754B are printedon the substrate 702, the capacitive pick-up areas 742, 752A, 754A,752B, and 754B are electrically isolated from the layer 798. The secondcapacitive pick-up area 744 is printed within the ticket identificationportion 708 over the strip 800B and thus is located in the channel 802B.The resistive element 746, which is connected to and extends between thecapacitive pick-up areas 742 and 744 of the integrity circuit element740, is printed on the ticket 700 so that the portion 748 of theresistive element 746 is located within the play field portion 706 ofthe ticket 700. FIG. 57 shows the ticket 700 when the lower blockinglayer 794 is printed as the patterned layer 808. The first capacitivepick-up area 742 of the integrity circuit element 740 is printed in theticket identification portion 708 and is located within the aperture812. The first capacitive pick-up area 742 thus is not printed over thepatterned layer 808 and is actually printed on the substrate 702 of theticket 700. Similarly, the capacitive pick-up area 752A of the datacircuit element 750A and the capacitive pick-up area 752B of the datacircuit element 750B are printed in the ticket identification portion708 and are located within the apertures 814A and 814B, respectively.The capacitive pick-up areas 752A and 752B of the data circuit elements750A and 750B are thus printed on the substrate 702 of the ticket 700.Consequently, because the capacitive pick-up areas 742, 752A, and 752Bare printed on the substrate 702, the capacitive pick-up areas 742,752A, and 752B are electrically isolated from the layer 808. The secondcapacitive pick-up area 744 of the integrity circuit element 740 and thesecond capacitive pick-up areas 754A and 754B of the data circuits 750Aand 750B are printed directly over the patterned layer 808, within theticket identification portion 708 of the ticket 700. The resistiveelement 746, which is connected to and extends between the capacitivepick-up areas 742 and 744 of the integrity circuit element 740, isprinted on the ticket 700 so that the portion 748 of the resistiveelement 746 is located within the play field portion 706 of the ticket700.

The third printing press station 766 prints the third layer 818 (shownin FIG. 58) which is a masking layer that masks the lower blocking layer794 and prevents visual interference from the lower blocking layer 794when a user inspects the play indicia 720A-H (shown in FIG. 61). Asshown in FIG. 58 the masking layer 818 is printed as a continuous layerthat covers both the play field portion 706 and the ticketidentification portion 708 of the ticket 700. In order not to interferewith the electrical signatures of the circuit elements 732A-H, 740,750A, and 750B, the electrical conductivity of the masking layer 818should be significantly less than the electrical conductivity of thecircuit elements 732A-H, 740, 750A, and 750B. In the preferredembodiment, the sheet resistivity of the masking layer 818 is greaterthan 10⁸ Ω/□. A suitable formulation for the masking layer 818 is givenin Table 6.

TABLE 6 Ink Formulation For The Masking Layer 818 material wt % Predasolrutile white 1300-PA 33.33% versamide 940 resin 22.22% ethanol 22.225%heptane 22.225%

The fourth printing station 768 prints the fourth layer 820 which is aprimer layer that provides a suitable surface for printing the playindicia 720A-H (shown in FIG. 61). As shown in FIG. 59, the primer layer820 is printed as a continuous layer that covers both the play fieldportion 706 and the ticket integrity portion 798 of the ticket 700. Inorder not to interfere with the electrical signatures of the circuitelements 732A-H, 740, 750A, and 750B, the electrical conductivity of theprimer layer 820 should be significantly less than the electricalconductivity of the circuit elements 732A-H, 740, 750A, and 750B. In thepreferred embodiment, the sheet resistivity of the primer layer 820 isgreater than 10⁸ Ω/□. Printing stations 770-774 provide the featuresprinted in the display portion 704 of the ticket 700 which, as shown inFIG. 60, include the name of the game 710, the rules for playing thegame 712, and the customized art work 714. The ink jet station 792prints the play indicia 720A-H, the validation number 726, the inventorycontrol number 728 and the bar code 730. As shown in FIG. 61 the playindicia 720A-H are printed directly on the primer layer 820 within theplay field portion 706 of the ticket 700. The validation number 726, theinventory control number 728 and the bar code 730 are also printeddirectly on the primer layer 820 but are located within the ticketidentification portion 708 of the ticket. Station 776 prints the back822 of the ticket 700 which, as shown in FIG. 62, can include additionalinformation 824 concerning the game.

Station 778 prints the fifth layer 826 which is a seal coat layer thatprotects the play indicia 720A-H and the validation number 726 againstabrasion. FIG. 63 illustrates the seal coat layer 826 which is printedon the ticket 700 so that the layer 826 covers all of the primer layer820 within the play field portion 706 and so that the seal coat layer826 covers the validation number 726 within the ticket identificationportion 708 of the ticket. In order not to interfere with the electricalsignatures of the circuit elements 732A-H, 740, 750A, and 750B, theelectrical conductivity of the seal coat layer 826 should besignificantly less that the electrical conductivity of the circuitelements 732A-H, 740, 750A, and 750B. In the preferred embodiment, thesheet resistivity of the seal coat layer 826 is greater than 10⁸ Ω/□. Asuitable formulation for the seal coat layer 826 is given in Walton,U.S. Pat. No. 4,726,608.

The next layer is a release coat layer, generally denoted as 828, thatis printed by the station 780. The release coat layer 828 is notcontinuous but instead in this embodiment consists of discreet layerportions 828A-828H that are associated with the play indicia 720A and adiscrete layer portion 828I that is associated with the validationnumber 726. Thus, as shown in FIG. 64, the release coat layer 828 isprinted on the seal coat layer 826 so that the release coat layerportion 828A covers the play indicia 720A. Similarly, the release coatlayer portion 828C covers the play indicia 720C and the release coatlayer portion 828F covers the play indicia 720F. In addition, therelease coat layer portion 828I covers the validation number 726. Therelease coat 828 serves two general functions. First, the release coat828 assures that layers which overlie the play indicia 720A-H and thevalidation number 726 can be removed to reveal the play indicia 720A-Hand the validation number 726. In addition, as explained with referenceto FIG. 75, the discrete release coat portions 828A-H help to ensurethat the electrical signatures of the indicia circuit elements 732A-Hchange when the layers overlying the play indicia 720A-H are removed toreveal the play indicia 720A-H. In order not to interfere with theelectrical signatures of the circuit elements 732A-H, 740, 750A, and750B, the electrical characteristics of the release coat layer 828should be significantly less than the electrical conductivity of thecircuit elements 732A-H, 740, 750A, and 750B. In the preferredembodiment, the sheet resistivity of the release coat layer 828 isgreater than 10⁸ Ω/□. However, since the release coat layer 828 does notcontact any of the capacitive pick-up areas 734A-H. 736A-H, 742A-H,744A-H, 752A-B, and 754A-B, a lesser sheet resistivity, for exampleabout 10⁷ Ω/□, would be acceptable. A suitable formulation for therelease coat layer 828 is given in Walton, U.S. Pat. No. 4,726,608.

Station 782 prints the next layer which is an opaque upper blockinglayer 830 that helps to protect the play indicia 720A-H, the validationsnumber 726 and portions of the circuit elements 732A-H, 740, 750A, and750B against surreptitious detection by candling. The preferredembodiment of the upper blocking layer 830 has a sheet resistivity thatis at least about 100 times greater than the sheet resistivity of thecircuit elements 732A-H, 740, 750A, and 750B. Consequently, in thepreferred embodiment the upper blocking layer 830 does not interferewith the electrical signatures of the circuit elements 732A-H, 740,750A, and 750B and there is no need to electrically isolate the circuitelements 732A-H, 740, 750A, and 750B from the upper blocking layer 830.Thus, shown in FIG. 65, in the preferred embodiment the upper blockinglayer 830 is printed as a continuous layer 832 that overlies the playfield portion 706 of the ticket 700 and overlies the validation number726 within the ticket integrity portion of the ticket 700. The playindicia 720A and the associated release coat portion 828A are shown inphantom for reference.

The upper blocking layer 830 can also be printed with materials thathave a lesser difference in conductivity relative to the circuitelements 732A-H, 740, 750A, and 750B as long as the configuration of thelayer 830 electrically isolates at least portions of the indicia circuitelements 732A-H. A suitable ink for the upper blocking layer 830 isgiven in Table 7.

TABLE 7 Ink Formulation For The Upper Blocking Layer 830 material wt %Heptane 34.1% Normal Propyl Acetate 30% Rosin Ester Resin 3330 10.2%Silicone Dispersant BYK 163 0.7% Carbon Black 350 13% Rubber Copolymer D1107 9.2% Calcium Carbonate 1.7% Polyethylene/PTFE wax blend 1%

Similar to the lower blocking layer 794, one of the functions of theupper blocking layer 830 is to obscure the play indicia 720A-H and thecircuit elements 732A-H. Consequently, the upper blocking layer 830should be as opaque as possible, a goal which is conveniently obtainedby using carbon black or other dark pigments in the ink used to printthe upper blocking layer 830. However, the presence of carbon black inthe ink used to print the upper blocking layer 830 can result in an inkformulation that is somewhat conductive. However, the ink formulation inTable 6 does provide a relatively high sheet resistivity which, in thiscase, is greater than about 20 MΩ/□. In addition, the ink formulation inTable 7 has a reduced graphic adhesiveness compared the to the inkpresented in Table 5 which is suitable for printing the lower blockinglayer 794. The ink presented in Table 7 therefore can be readily removedfrom the ticket 700 when the play spot areas 716A-H are removed toreveal the underlying play indicia 720A-H.

FIG. 66 illustrates an alternative configuration of the upper blockinglayer 830 which is a barred layer 834 that is printed with a materialwhich is minimally conductive relative to the material used to print thecircuit elements 732A-H, 740, 750A, and 750B. The barred layer 834includes laterally spaced-apart strips 836A and 836B which aresubstantially opaque and longitudinally span the play field portion 706.The strips 836A-B also cover the validation number 726 within the ticketidentification portion 708 of the ticket 700. The spaced-apart strips836A and 836B define channels 838A and 838B for the resistive elements738A-H of the indicia circuit elements 732A-H. The channels 838A and838B contain the material used to print the upper blocking layer 830.The space between the strip 836A and the interface 804 between the playfield portion 706 and the display portion 704 and the space between thestrips 836A and 836B define channels 840A and 840B for the capacitivepick-up areas 734A-H and 736A-H of the indicia circuit elements 732A-H.The layer that is exposed by the channels 840A and 840B is the seal coatlayer 826 which, as previously stated, has a sheet resistivity greaterthan 10⁸ Ω/□. The configuration of the barred layer 834 thuselectrically isolates the capacitive pick-up areas 734A-H and 736A-H ofthe indicia circuit elements 732A-H from the minimally conductive strips836A and 836B. The barred layer 834 is the preferred form of the upperblocking layer 830 when the lower blocking layer 794 is printed as thebarred layer 798 shown in FIG. 53. The upper blocking layer 830 isprinted in registry with the lower blocking layer 794 so that thespaced-apart strips 836A and 836B of the upper barred layer 834 arealigned with the spaced-apart strips 800A and 800B of the lower barredlayer 798. Consequently, the channels 838A and 838B and the channels840A and 840B which are defined by the upper barred layer 834 coincidewith the channels 802A and 802B and the channels 806A and 806B,respectively, which are defined by the lower barred layer 798. In FIG.66, the play indicia 720A and the associated release coat portion 828Aare shown in phantom for reference. The play indicia 720A and theassociated release coat portion 828A are printed on the ticket 700 sothat the play indicia 720A and the associated release coat portion 828Aare aligned with both the strip 836A of the upper blocking layer 830 andthe strip 800A of the lower blocking layer 794. The play indicia 720Aand the associated release coat portion 828A are thus within both thechannel 838A defined by the upper blocking layer 830 and the channel802A defined by the lower blocking layer 794.

FIG. 67 illustrates another embodiment of the upper blocking layer 830which includes a patterned layer 842 that is printed with a materialthat is minimally conductive relative to the circuit elements 732A-H,740, 750A, and 750B. The patterned layer 842, which is substantiallyopaque, overlies the entire play field portion 706 of the ticket 700 andalso covers the validation number 726 within the ticket identificationportion 708 of the ticket 700. The patterned layer 842 defines severalapertures 844-H which electrically isolate portions of the indiciacircuit elements 732A-H. Specifically, the apertures 844-H arepositioned and shaped to coincide with the first capacitive pick-upareas 734A-H of the indicia circuit elements 732A-H. The exposed layerwithin the apertures 844A-H is the seal coat layer 826 which has a sheetresistivity greater than 10⁸ Ω/□. The patterned layer 842 is thepreferred form of the upper blocking layer 830 when the lower blockinglayer 794 is printed in the patterned layer 808 shown in FIG. 54. Theupper blocking layer 830 is printed in registry with the lower blockinglayer 794 so that the apertures 844A-H defined by the patterned layer842 are aligned with the apertures 810A-H defined by the lower patternedlayer 808. Thus, for example, the aperture 844A of the upper blockinglayer 830 coincides with the aperture 810A of the lower blocking layer794. In FIG. 67, the play indicia 720A and the associated release coatportion 828A are shown in phantom for reference. The play indicia 720Aand the associated release coat layer portion 828A are printed on theticket adjacent the aperture 844A in the upper blocking layer 830.Because the upper blocking layer 830 is printed in registry with thelower blocking layer 794, the play indicia 720A and the associaterelease coat layer portion 828A are also printed adjacent the aperture810A in the lower blocking layer 794. A suitable ink for printing theupper blocking layer 830 794 either as the barred layer 834 or as thepatterned layer 842 was given previously in Table 3.

The station 784 prints the next layer which consists of the indiciacircuit elements 732A-H. The appearance of the ticket 700 at this pointvaries according to the configuration of the upper blocking layer 830.FIG. 68 illustrates the ticket 700 when the upper blocking layer 830 isprinted as the continuous layer 832. Since in the preferred embodimentthe continuous layer 832 is printed with a material that does notinterfere with the electrical signatures of the circuit elements 732A-H,740, 750A, and 750B there is no need to isolate any portions of theindicia circuit elements 732A-H from the upper blocking layer 830.Consequently, the indicia circuit elements 732A-H are printed directlyon the continuous layer 832. The indicia circuit elements 732A-H arepositioned to align with the play indicia 720 so that the resistiveelements 738 overlie the play indicia 720. Thus, for example, theindicia circuit element 732A is printed on the layer 832 to align withthe play indicia 720A and the associated release coat layer portion 828A(shown in phantom) so that the resistive element 738A overlies the playindicia 720A and the associated release coat layer portion 828A.

FIG. 69 illustrates the form of the ticket 700 when the upper blockinglayer 830 is printed as the barred layer 834. In FIG. 69 the playindicia 720A and the associated release coat layer portion 828A areshown in phantom for reference. However it should be kept in mind thatneither the play indicia 720A and nor the associated release coat layerportion 828 would be visible because of the upper blocking layer 830.The indicia circuit elements 732A-H are printed on the ticket 700 sothat the first capacitive pick-up areas 734A-H and the second capacitivepick-up areas 736A-H are printed in registry with the channels 840A and840B defined by the barred layer 834. For example, the indicia circuitelement 732A is printed on the ticket 700 so that the first and secondcapacitive pick-up areas 734A and 734B are positioned within the channel840A. Similarly, the indicia circuit element 732F is printed on theticket 700 so that the first and second capacitive pick-up areas 734Fand 736F are positioned within the channel 840B. As noted earlier, thelayer exposed in the channels 840A and 840B is the seal coat layer 826which has a sheet resistivity greater than about 10⁸ Ω/□. The channels840A and 840B defined by the barred layer 834 thus electrically isolatethe first capacitive pick-up areas 734A-H and the second capacitivepick-up areas 736A-H of the indicia circuit elements 732A-H from theminimally conductive strips 838A and 838B. Moreover, the upper blockinglayer 830 is printed in registry with the lower blocking layer 794 sothat the upper channels 840A and 840B are aligned with the lowerchannels 802A and 802B. The first capacitive pick-up areas 734A-H andthe second capacitive pick-up areas 736A-B of the indicia circuitelements 732A-H therefore are electrically isolated from the minimallyconductive strips 800A and 800B in the lower blocking layer 794.

The indicia circuit elements 732A-H are also printed on the ticket 700so that the resistive elements 738A-H are aligned with the strips 836A-Band overlie the play indicia 720A-H. For example, the indicia circuitelement 732A is printed on the ticket 700 so that the resistive element738A is printed on the strip 836A, within the channel 838A, and overliesthe play indicia 720A and the associated release coat layer portion 828A(shown in phantom). Similarly, the indicia circuit element 732G isprinted on the ticket 700 so that the resistive element 738G is printedon the strip 836B, within the channel 838B, and overlies the playindicia 720G (not shown) and the associated release coat layer portion828G (not shown). In addition, the strips 826A and 836B of the upperbarred blocking layer 834 are printed in registry with the strips 800Aand 800B of the lower barred blocking layer 798. Consequently, the playindicia 720A-H are intermediate the strips 836A-B and 800A-B of theupper and lower barred blocking layers, 834 and 798 respectively, and soare protected against surreptitious detection by candling.

FIG. 70 illustrates the form of the ticket 700 when the upper blockinglayer 830 is printed as the patterned layer 842. The play indicia 720Aand the associated release coat layer portion 828A are shown in phantomfor reference. However it should be kept in mind that neither the playindicia 720A and nor the associated release coat layer portion 828 wouldbe visible because of the upper blocking layer 830. The indicia circuitelements 732A-H are printed on the ticket 700 so that the firstcapacitive pick-up areas 734A-H are in registry with and positionedwithin the apertures 844A-H defined by the upper patterned blockinglayer 842. For example, the first capacitive pick-up area 734A of theindicia circuit element 732A is in registry with and positioned withinthe aperture 844A. Similarly, the first capacitive pick-up area 734F ofthe indicia circuit element 732A is in registry with and positionedwithin the aperture 844F. As noted earlier, the layer exposed in theapertures 844A-H is the seal coat layer 826 which has a sheetresistivity that is greater than about 10⁸ Ω/□. The apertures 844A-Ddefined by the upper patterned blocking layer 842 thus electricallyisolate the first capacitive pick-up areas 734A of the indicia circuitelements 732A-H from the minimally conductive layer 842. Moreover, theupper patterned blocking layer 842 is printed in registry with the lowerpatterned blocking layer 808 so that the upper apertures 844A-H arealigned with the lower apertures 810A-H. The first capacitive pick-upareas 734A-H of the indicia circuit elements 732A-H therefore areelectrically isolated from the minimally conductive layer 808 as well.The indicia circuit elements 732A-H are also printed on the ticket 700so that the resistive elements 738A-H overlie the play indicia 720A-H.For example, the resistive element 738A of the indicia circuit element732A overlies the play indicia 720A. Similarly, the resistive element738F is printed on the ticket 700 to overlie the play indicia 720F (notshown). Moreover, because the upper patterned blocking layer 842 isprinted in registry with the lower patterned blocking layer 808, theplay indicia 720A-H are protected against candling.

Printing press station 786 prints the next layer on the ticket which isa removable scratch-off coating 846. As shown in FIG. 71, thescratch-off coating 846 is printed as a continuous layer that covers theplay field portion 706 of the ticket 700 and the validation number 726within the ticket identification portion 708 of the ticket. In order notto interfere with the electrical signatures of the circuit elements732A-H, 740, 750A, and 750B, the electrical conductivity of thescratch-off coating 846 should be significantly less that the electricalconductivity of the circuit elements 732A-H, 740, 750A, and 750B. In thepreferred embodiment, the sheet resistivity of the scratch-off coating846 is greater than 10⁸ Ω/□. A suitable formulation for the scratch-offcoating 846 is given in Walton, U.S. Pat. No. 4,726,608. The remainingtwo printing press stations 788 and 790 apply overprint graphics such asthe play spot areas 716A-H, the play spot graphics 718, thevoid-if-removed area 722, and the overprint graphics 724 and thusprovide the finished appearance of the ticket 700 as shown in FIG. 49.

The structure of the ticket 700 can be simplified by replacing theseparate seal coat layer 826, shown in FIG. 63, and the discontinuousrelease coat layer 828, shown in FIG. 64, with a combined seal-releasecoat layer, generally denoted as 848. Like the release coat 828, thecombined seal-release coat layer 848 is not continuous but insteadconsists of discreet layer portions 848A-H that are associated with theplay indicia 720A-H and a discrete layer portion 8481 that is associatedwith the validation number 736. For example, as shown in FIG. 72 thecombined seal-release coat layer 848 is printed on the primer 820 sothat the seal-release coat layer portion 848A covers the play indicia720A. Similarly, the combined seal-release coat portion 848G covers theplay indicia 720G. In addition, the seal-release coat portion 8481covers the validation number 726. The combined seal-release coat 848protects the play indicia 720A-H and the validation number 726 againstabrasion. The combined seal-release coat 848 also ensures that thelayers which overlie the play indicia 720A-H and the validation number726 can be removed to reveal the play indicia 720A-H and the validationnumber 726. In addition, as explained in reference to FIG. 75, thediscrete seal-release coat portions 848A-H help to ensure that theelectrical signatures of the indicia circuit elements 732A-H change whenthe layers overlying the play indicia 720A-H are removed. In order notto interfere with the electrical signatures of the circuit elements732A-H, 740, 750A, and 750B, the electrical conductivity of theseal-release coat layer 848 should be significantly less than theelectrical conductivity of the circuit elements 732A-H, 740, 750A, and750B. In the preferred embodiment, the sheet resistivity of theseal-release coat 848 is greater than about 10⁸ Ω/□. However, since theseal-release coat layer 848 does not contact any of the capacitivepick-up areas 734A-H. 736A-H, 742A-H, 744A-H, 752A-B, and 754A-B, alesser sheet resistivity, for example about 10⁷ Ω/□, would beacceptable.

The printing sequence for the ticket changes slightly when theseal-release coat 848 is used instead of the separate seal coat layer826 and the separate release coat layer 828. Instead of printing theseal coat 826 on the primer layer 820, station 778 prints theseal-release coat 848 on the primer layer. Station 780 then prints theupper blocking layer 830 as previously described with reference to FIGS.65-67 and station 782 prints the indicia circuit elements 732A-H aspreviously described with reference to FIGS. 68-70. It should be notedthat when the combined seal-release coat 848 is used the primer layer820, instead of the seal coat layer 826, is exposed in the channels 840Aand 840B defined by the upper barred blocking layer 834 and in theapertures 844A-D defined by the upper patterned blocking layer 842.However, like the seal coat layer 826 the primer layer 820 has a sheetresistivity that is greater than 10⁸ Ω/□. The ticket 700 thereforefunctions in the same manner as described with reference to FIGS. 65-70when the seal-release coat layer 848 is used instead of the separateseal coat 826 and the separate release coat 828. This printing sequencealso makes it possible to apply the indicia circuit elements 732A-Htwice, at stations 782 and 784. As explained below with reference toFIGS. 75-76, portions of the indicia circuit elements 732A-H are removedwhen portions of the scratch-off layer 846 within the play spot areas716A-H are removed to reveal the play indicia 720A-H. Consequently, theink used to print the indicia circuit elements 732A-H has a reducedgraphic adhesiveness relative to the ink used to print the integritycircuit elements 740 and the data circuit elements 750A-B. The reducedgraphic adhesiveness of the ink used to print the indicia circuitelements 732A-H, coupled with the high speed of the gravure printingpress 760 can result in small holes, known as picking, in the indiciacircuit elements 732A-H. FIGS. 73 and 74 present an enlargedrepresentation of one of the indicia circuit elements 732A-H, forexample, the element 732A. In FIG. 73 a small portion 850 of the indiciacircuit element 732A has been picked-off during the printing of theelement 732A. Similarly, in FIG. 74 a different small portion 852 of theindicia circuit element 732A has been picked-off during the printing ofthe element 732A. The resulting discontinuity in the indicia circuitelement 732A in FIGS, 73 and 74 can lead to errors in detecting theelectrical signature of the indicia circuit element 732A. However, ifthe two illustrations of the indicia circuit element 732A in FIGS. 73and 74 are superimposed, for example, by laying the indicia circuitelement 732A in FIG. 74 over the indicia circuit element 732A in FIG. 73in registry therewith, the combined image does not suffer from anydiscontinuities. Therefore, by printing the indicia circuit elements732A-H at two of the stations, for example at the stations 782 and 784,such that the two layers of the indicia circuit elements 732A-H are inregistry with each other, discontinuities in the printed indicia circuitelements 732A-H can be reduced or eliminated.

FIG. 75 presents an enlarged view of one of the indicia circuitelements, for example circuit element 720A, and the underlyingassociated play indicia 720A. FIG. 75 also shows the position andconfiguration of the associated release coat layer portion 828A or theassociated seal-release coat layer portion 848A. As previouslyexplained, the release coat 828 or the seal-release coat 848 isinterposed between the play indicia 732A-H and the indicia circuitelements 732A-H. Although not shown, it is to be understood that theupper blocking layer 830 is also interposed between the release coat 828or the seal-release coat 848 and the indicia circuit elements 732A-H. Asshown in FIG. 75, in the preferred embodiment the resistive element 738Ais printed over either the release coat layer portion 828A or theseal-release coat layer portion 848A so that a portion 854 extendsbeyond the release coat layer portion 828A or the seal-release coatlayer portion 848A thereby ensuring that the electrical signature of thecircuit element 732 changes when the layers overlying the play indicia720 are lifted or removed.

FIG. 76 shows an alternative embodiment of an indicia circuit element856 according to the invention. Like the indicia circuit elements732A-H, the indicia circuit element 856 includes the first capacitivepick-up area 734, the second capacitive pick-up area 736, and theresistive element 738. The main difference between the indicia circuitelement 856 and the indicia circuit elements 732A-H is that the secondcapacitive pick-up area 736 is no longer aligned with the firstcapacitive pick-up area 734 but instead is aligned with the resistiveelement 738. This change is of primary importance when the upperblocking layer 830 is printed as the barred layer 834 in which case thesecond capacitive pick-up area 736 of the indicia circuit element 856 isprinted on the ticket 700 so that the second capacitive pick-up area 736either is printed on the strip 836A, within the channel 838A, and or isprinted on the strip 836B, within the channel 838B. In all otherrespects, the indicia circuit element 856 operates in the same manner asthe indicia circuit elements 732A-H.

The complete structure of the ticket 700 offers several securityadvantages. The lower and upper blocking layers 794 and 830 help toprotect against surreptitious detection of the play indicia 720A-H andthe circuit elements 732A-H, 740, 750A, and 750B by candling orfluoresence. The integrity circuit 740 provides a way of determining ifan attempt has been made to alter the bar code 730, for example, bycutting and replacing the bar code 730. The data circuits 750A and 750Boffer at least partial ticket authenticity and integrity information inbinary form. The indicia circuit elements 732A-H both protect the playindicia 720A-H against fraudulent manipulation and provide a way toverify the gaming value of the ticket 700. As noted previously withreference to FIGS. 75 and 76, in the preferred embodiment the indiciacircuit elements 732A-H are printed over either the release coatportions 828A-H or the seal-release coat portions 848A-H so thatportions 854A-H of the resistive elements 738A-H extend beyond therelease coat layer portions 828A-H or the seal-release coat layerportions 848A-H. When one of the play spot areas 716A-H, for example theplay spot area 716A, is lifted to reveal the underlying play indicia720A, the resistive element 738A will be fractured because the portion854A of the resistive element 738A remains affixed to the ticket 700.Consequently, if an attempt is made thereafter to replace the play spotarea 716A and the fractured resistive element 738A, the resulting changein the electrical signature of the indicia circuit element 732A isdetected by the sensor array 502 of the electronic verification machine500. In addition, when a play spot area such as the play spot area 716Ais legitimately removed to reveal the play indicia 720A, the electricalcontinuity between the capacitive pick-up area 734A and 736A of theindicia circuit element 732A is broken when the resistive element 738Ais removed with the play spot area 716A. The resulting change in theelectrical signature of the indicia circuit element 738A can then bedetected by the sensor array 502 of the electronic verification machine500, thereby providing a way to determine the gaming value of the ticket700.

IX. A Marker Ticket In Accordance With The Invention

FIGS. 77-83 show a marker ticket 860 which can be used with theelectronic verification machine 500 (shown in FIGS. 38-40). The markercard 860 is the type used to record a user's choices relative to pre-setoptions. For example, marker cards, such as the marker card 860, can beused in playing games such as Bingo or Keno. Marker cards like the card860 are also used to record a user's choice of numbers or other indiciain on-line lottery games. The marker card 860, like the probability gameticket 700, can be used in conjunction with the electronic verificationmachine 500 of the type shown in FIGS. 38-40. FIG. 77 presents thefinished appearance of the card 860 which is printed on a substrate,such as paper or card stock, and includes various printed informationsuch as the identity or title 864 of the card 860, inventory data 866,and a machine-readable bar code 868. A boarder 869 delineates the playarea of the card 860 and is printed as overprint graphics. The card 860also includes an indicia-array area 870 that has a group of indicia spotareas 872A-L, each of which includes an overlay indicia 874A-L. Theindicia spot areas 872A-L and the overlay indicia 874A-L are printed asoverprint graphics. Each of the indicia spot areas 872A-L covers a playindicia 876A-L (shown in FIGS. 79-81) that is identical to thecorresponding overlay indicia 874A-L. For example, the overlay indicia874E in indicia spot area 872E is a diamond and the play indicia 876E(shown in FIGS. 79-81), which is located beneath the indicia spot area872E is also a diamond. The indicia spot area 872A has been removed toreveal the underlying associated play indicia 876A. The overlay indicia874A-L and the play indicia 85A-L define longitudinal data channels877A-C. For example, the overlay indicia 874A-D and the associated playindicia 876A-D are in the data channel 877A and the overlay indicia8741-L and the associated play indicia 876I-L are in data channel 877C.The overlay indicia 874A-L and the play indicia 876A-L are used torepresent the pre-set options among which a user can choose.

The card 860 also includes circuit elements, generally denoted as 878,which when coupled to the sensor array 502 of the electronicverification machine 500 serve to verify or record the user's chosenoptions. As shown in FIG. 78 the card 860 has three circuit elements878A-C, each of which includes a resistive element, generally denoted as880, and an upper and a lower terminal capacitive pick-up area,generally denoted as 882 and 884, which are connected to and extend fromthe opposites ends 888 and 890 of the resistive element 880. Forexample, the circuit element 878A includes the resistive element 880Aand the two terminal capacitive pick-up areas 882A and 884A which arealigned with each other and are connected to and laterally extend fromthe first end 888A and the second end 890A, respectively, of theresistive element 880A. Each of the circuit element 878 also includesintermediate capacitive pick-up areas, generally denoted as 892, thatare aligned with the terminal capacitive pick-up areas 888 and 890 andare connected to the resistive elements 880 intermediate the terminalcapacitive pick-up areas 888 and 890. For example, the circuit element878A has three intermediate capacitive pick-up areas 892A, 892A′, and892A″, that are aligned with the terminal capacitive pick-up areas 888Aand 890A and are connected to the resistive element 880A intermediatethe terminal capacitive pick-up areas 888A and 890A. Similarly, thecircuit element 878B has three intermediate capacitive pick-up areas892B, 892B′, and 892B″, that are aligned with the terminal capacitivepick-up areas 888B and 890B and are connected to the resistive element880B intermediate the terminal capacitive pick-up areas 888B and 890B.The circuit elements 878A-C are positioned on the card 860 so that theresistive elements 880A-C are aligned with and positioned in the datatracks 877A-C defined by the overlay indicia 874A-L and the play indicia876A-L and so that portions 894A-L of the resistive elements 880A-L arealigned with the overlay indicia 874A-L and with the play indicia876A-L. For example, the portion 894A-D of the resistive element 880Aare aligned with the overlay indicia 874A-D and with the associated playindicia 876A-D. Similarly, the portions 894I-L of the resistive element880C are aligned with the overlay indicia 874I-L and with the associatedplay indicia 876I-L.

Several layers are needed to provide the finished card 860 shown in FIG.77. As shown in FIG. 79, the first layer 896 is printed directly on thesubstrate 862 and includes the play indicia 876A-L. The first layer 896can also include the title 864, the inventory data 866, and the bar code868. The play indicia 876A-L are printed on the card substrate 862 withthe indicia-array portion 870 and are positioned to define the datachannels 877A-C. For example, the play indicia 876E-H define the datachannel 877B. In the preferred embodiment, the play indicia 876A-L areprinted in a different color than the overlay indicia 874A-L in order tomake it easier for a user of the card 860 to determine which if theoverlay indicia 874A-L have been removed. The next layer is a seal coatlayer 898 that protects the play indicia 876A-L against abrasion. Asshown in FIG. 80, in the preferred embodiment the seal coat layer 898 isprinted within the indicia-array portion 870 of the card 860 as acontinuous layer that overlies the play indicia 876A-L. In order not tointerfere with the electrical signatures of the circuit elements 878A-Cthe electrical conductivity of the seal coat layer 898 should besignificantly less that the electrical conductivity of the circuitelements 878A-C. In the preferred embodiment, the sheet resistivity ofthe seal coat layer 898 is greater than 10⁸ Ω/□. A suitable formulationfor the seal coat layer 898 is given in Walton, U.S. Pat. No. 4,726,608.

Next, a release coat 900 is printed on the card 860 so that the releasecoat 900 overlies the play indicia 876A-L but preferably is not locatedbelow any of the capacitive pick-up areas 882, 884, and 892 of thecircuit elements 878A-C. For example, as shown in FIG. 81 the releasecoat 900 can be printed as a barred layer 902 that includeslongitudinally spaced-apart strips 904A-D which are printed within andlaterally span the indicia-array portion 870 of the card 860. Each ofthe strips 904A-D covers a row of play indicia 876A-L. For example, thestrip 904A laterally spans the indicia-array portion 870 of the card 860and covers the play indicia 876A, 876E, and 876I. Similarly, the strip904B covers the play indicia 876B, 876F, and 876J, the strip 904C coversthe play indicia 976C, 876G, and 876K, and the strip 904D covers theplay indicia 876D, 876H, and 876L. The material exposed between twoadjacent strips 904A-D, for example the strip 904A and the strip 904B,is the seal coat layer 898 and the material exposed adjacent the strips904A-D but outside of the indicia-array portion 870 of the card 860 isthe substrate 862. Alternatively, as shown in FIG. 82, the release coatlayer 900 can be printed as a discontinuous layer 906 that includesdiscreet release coat spots 908A-L each of which covers an associatedplay indicia 876A-L. For example, the release coat spot 908A covers theplay indicia 876A and the release coat spot 908G covers the play indicia876G. Within the indicia-array portion 870 of the card 860 the materialexposed between adjacent release coat spots 908A-L, for example therelease coat spot 908B and the release coat spot 908F, is the seal coatlayer 898. Outside of the indicia-array portion 870 of the card 860 thematerial exposed adjacent the release coat spots 908A-L is the substrate862. In order not to interfere with the electrical signatures of thecircuit elements 878A-C the electrical conductivity of the release coatlayer 900 should be significantly less that the electrical conductivityof the circuit elements 878A-C. In the preferred embodiment, the sheetresistivity of the release coat layer 900 is greater than 10⁸ Ω/□.However, since the release coat layer 900 does not underlie any of thecapacitive pick-up areas 882, 884, and 892, a lesser sheet resistivity,for example about 10⁷ Ω/□, would be acceptable. A suitable formulationfor the release coat layer 900 is given in Walton, U.S. Pat. No.4,726,608.

Alternatively, a combined seal-release coat 910 can be used instead ofthe separate seal coat and release coat layers 898 and 900 shown inFIGS. 80-82, in which case, the combined seal-release coat 910 isprinted on the card 860 so that the seal-release coat 910 overlies theplay indicia 876A-L but is not located below any of the capacitivepick-up areas 882, 884, and 892 of the circuit elements 878A-C. Forexample, as shown in FIG. 83 the seal-release coat 910 can be printed asa barred layer 912 that includes longitudinally spaced-apart strips914A-D which are printed within and laterally span the indicia-arrayportion 870 of the card 860. Each of the strips 914A-D covers a row ofplay indicia 876A-L. For example, the strip 914A laterally spans theindicia-array portion 870 of the card 860 and covers the play indicia876A, 876 E, and 876I. Similarly, the strip 914B covers the play indicia876B, 876F, and 876J, the strip 914C covers the play indicia 976C, 876G,and 876K, and the strip 914D covers the play indicia 876D, 876H, and876L. The exposed material around any of the strips 914A-D is thesubstrate 862. Alternatively, as shown in FIG. 84, the seal-release coatlayer 910 can be printed as a discontinuous layer 916 that includesdiscreet seal-release coat spots 918A-L each of which covers anassociated play indicia 876A-L. For example, the seal-release coat spot918A covers the play indicia 876A and the seal-release coat spot 918Gcovers the play indicia 876G . The exposed material around any of theseal-release coat spots 918A-L is the substrate 862. In order not tointerfere with the electrical signatures of the circuit elements 878A-Cthe electrical conductivity of the seal-release coat layer 910 should besignificantly less that the electrical conductivity of the circuitelements 878A-C. In the preferred embodiment, the sheet resistivity ofthe seal-release coat layer 910 is greater than 10⁸ Ω/□. However, sincethe seal-release coat layer 910 does not underlie any of the capacitivepick-up areas 882, 884, and 892, a lesser sheet resistivity, for exampleabout 10⁷ Ω/□, would be acceptable.

The circuit elements 878A-C are printed on the card 860 immediatelyafter either the release coat 900 or the seal-release coat 910. Sincethe portions 894A-L of the resistive elements 880A-C are removed whenthe indicia spot areas 872A-L and associated portions of the scratch-offlayer 920 are removed to revel the play indicia 876A-L, the ink used toprint the circuit elements 878A-C should have a relatively reducedadhesiveness. In addition, the ink used to print the circuit elementsshould have a relatively high conductivity. In the preferred embodiment,the ink used to print the circuit elements 878A-C has a sheetresistivity of about 8 Ω/□. A suitable formulation for the ink used toprint the circuit elements 878A-L was given previously in Table 3.

FIG. 85 illustrates the configuration of the card 860 when the circuitelements 878A-C are printed over the barred release coat layer 902. Asnoted earlier with reference to FIG. 78, the circuit elements 878A-C arepositioned on the card 860 so that the resistive elements 880A-C arealigned with and positioned in the data tracks 877A-C. Each resistiveelement 880A therefore overlies a column of the play indicia 876A-L andthe portions 894A-L of each resistive element 880A-D directly overlieone of the play indicia 876A-L. For example, the circuit element 878Aoverlies the play indicia 876A-D and the portions 894A-D of theresistive element 880A directly overlie the play indicia 876A-D.Similarly, the circuit element 878B overlies the play indicia 876E-H andthe portions 894E-H of the resistive element 880B directly overlie theplay indicia 876E-H. In addition, the circuit element 878C overlies theplay indicia 876I-L and the portions 894I-L of the resistive element880C directly overlie the play indicia 876I-L. Thus, although the playindicia 876A and 876G are shown for reference, it should be kept in mindthat the play indicia 876A and 876G would not actually be visiblebecause of the overlying portions 894A and 894G of the resistiveelements 880A and 880B, respectively. Similarly, the play indicia 876Iand 876J, although shown for reference, would not actually be visiblebecause of the overlying portions 894I and 894J of the resistive element880C. As previously noted with reference to FIG. 81, each of thelongitudinally spaced-apart strips 904A-D of the barred release coat 902covers a row of play indicia 876A-L so that within the play indiciaarray portion 870 the exposed material between adjacent strips 904A-D isthe seal coat layer 898. Moreover, outside of the indicia array portion870 the exposed material adjacent the strips 904A-D is the substrate862. Consequently, the terminal capacitive pick-up areas 882A-C and884A-C are printed directly on the substrate 862, as are theintermediate capacitive pick-up areas 89A, 892A′, and 892A″ of thecircuit element 878A. The intermediate capacitive pick-up areas 892B,892B′, and 892B″ of the circuit element 878B and the intermediatecapacitive pick-up areas 892C, 892C′, and 892C″ of the circuit element878C are printed on the seal coat layer 898. FIG. 86 illustrates theconfiguration of the card 860 when the circuit elements 878A-C areprinted over the discontinuous release coat layer 906. The circuitelements 878A-C are positioned on the card 860 so that the resistiveelements 880A-C are aligned with and positioned in the data tracks877A-C. Each resistive element 880A therefore overlies a column of theplay indicia 876A-L and the portions 894A-L of each resistive element880A-D directly overlie one of the play indicia 876A-L. Consequently,although shown for reference the play indicia 876A, 876G, 876I, and 876Jwould not be visible because of the overlying portions 894A, 894G, 894I,and 894J of the resistive elements 880A-C. As noted previously withreference to FIG. 82, within the indicia-array portion 870 of the card860 the material exposed between adjacent release coat spots 908A-L, forexample the release coat spot 908B and the release coat spot 908F, isthe seal coat layer 898. In addition, outside of the indicia-arrayportion 870 of the card 860 the material exposed adjacent the releasecoat spots 908A-L is the substrate 862. printed directly on thesubstrate 862, as are the intermediate capacitive pick-up areas 89A,892A′, and 892A″ of the circuit element 878A. The intermediatecapacitive pick-up areas 892B, 892B′, and 892B″ of the circuit element878B and the intermediate capacitive pick-up areas 892C, 892C′, and892C″ of the circuit element 878C are printed on the seal coat layer898.

FIG. 87 illustrates the configuration of the card 860 when the circuitelement 878A-C are printed on the barred seal-release coat 912. Thecircuit elements 878A-C are positioned on the card 860 so that theresistive elements 880A-C are aligned with and positioned in the datatracks 877A-C. Each resistive element 880A therefore overlies a columnof the play indicia 876A-L and the portions 894A-L of each resistiveelement 880A-D directly overlie one of the play indicia 876A-L.Consequently, although shown for reference the play indicia 876A, 876G,876I, and 876J would not be visible because of the overlying portions894A, 894G, 894I, and 894J of the resistive elements 880A-C. As notedearlier with reference to FIG. 83, the exposed material around any ofthe strips 914A-D is the substrate 862. Consequently, all of theterminal capacitive pick-up areas 882A-C and 884A-C and all of theintermediate capacitive pick-up areas 892A, 892A′, 892A″, 892B, 892B′,892B″, 892C, 892C′, and 892C″ are printed directly on the substrate 862.

FIG. 88 illustrates the configuration of the card 860 when the circuitelements 878A-C are printed over the discontinuous seal-release coatlayer 916. The circuit elements 878A-C are positioned on the card 860 sothat the resistive elements 880A-C are aligned with and positioned inthe data tracks 877A-C. Each resistive element 880A therefore overlies acolumn of the play indicia 876A-L and the portions 894A-L of eachresistive element 880A-D directly overlie one of the play indicia876A-L. Consequently, although shown for reference the play indicia876A, 876G, 876I, and 876J would not be visible because of the overlyingportions 894A, 894G, 894I, and 894J of the resistive elements 880A-C. Aspreviously noted with reference to FIG. 84, the exposed material aroundany of the seal-release coat spots 918A-L is the substrate 862.Consequently, all of the terminal capacitive pick-up areas 882A-C and884A-C and all of the intermediate capacitive pick-up areas 892A, 892A′,892A″, 892B, 892B′, 892B″, 892C, 892C′, and 892C″ are printed directlyon the substrate 862.

A scratch-off coating 920 is then printed on the card 860 so that thescratch-off coating 920 span the entire indicia array portion 870 of thecard 860 and covers all of the circuit elements 878A-C, as shown in FIG.89. In order not to interfere with the electrical signatures of thecircuit elements 878A-C the electrical conductivity of the scratch-offcoating 920 should be significantly less that the electricalconductivity of the circuit elements 878A-C. In the preferredembodiment, the sheet resistivity of the scratch-off coating 920 isgreater than 10⁸Ω/□. A suitable formulation for the scratch-off coating920 is given in Walton, U.S. Pat. No. 4,726,608. The boarder 869, theindicia spots areas 872A-L and the overlay indicia 874A-L are thenprinted as overprint graphics to give the card 860 the finishedappearance shown in FIG. 77.

The operation of the circuit elements 878A-C is best explained withreference to FIGS. 77, 79, and 85-88. Each of the capacitive pick-upareas 882A-C , 884A-C , 892A, 892A′, 892A″, 892B, 892B′, 892B″, 892C,892C′, and 892C″ is sized, shaped, and positioned on the card 860 sothat each of the capacitive pick-up areas 882A-C , 884A-C, 892A, 892A′,892A″, 892B, 892B′, 892B″, 892C, 892C′, and 892C″ can capacitivelycouple with either the excitation plate 576 or one of the sensor plates574 of the sensor array 502 in the electronic verification machine 500.Consequently, all of the intermediate capacitive pick-up areas 892A,892A′, 892A″, 892B, 892B′, 892B″, 892C, 892C′, and 892C″ function asboth excitation and sensor capacitive pick-up areas when the card 860 iscoupled to the electronic verification machine 500. The terminalcapacitive pick-up areas 882A-C and 884A-C, however, function only aseither an excitation capacitive pick-up area or a sensor capacitivepick-up area depending on the direction in which the card 860 movesthrough the electronic verification machine 500. For example, if thecard moves through the electronic verification machine 500 so that theterminal capacitive pick-up areas 882A-C first couple with the sensorarray 502, then the terminal capacitive pick-up areas 882A-C functiononly as excitation capacitive pick-up areas and the terminal capacitivepick-up areas 884A-C function only as sensor capacitive pick-up areas.Alternatively, if the card moves through the electronic verificationmachine 500 so that the terminal capacitive pick-up areas 884A-C firstcouple with the sensor array 502, then the terminal capacitive pick-upareas 884A-C function only as excitation capacitive pick-up areas andthe terminal capacitive pick-up areas 882A-C function only as sensorcapacitive pick-up areas. For ease of explanation, in the followingdiscussion it is to be understood that the card 860 moves through theelectronic verification machine 500 so that the terminal capacitivepick-up areas 882A-C first couple with the sensor array 502 and sofunction only as excitation capacitive pick-up areas. Referring now toFIGS. 85-88, when the card 860 first couples with the sensor array 502,the terminal capacitive pick-up area 882C serves as an excitationcapacitive pick-up area and the intermediate capacitive pick-up area892C serves as a sensor capacitive pick-up area. In addition, theterminal capacitive pick-up area 892C is joined to the intermediatecapacitive pick-up area 892C by the portion 894I of the resistiveelement 880C. The capacitive pick-up areas 882C and 892C and theassociated portion 8941 of the resistive element 880C therefore form aU-shaped circuit element. As the card 860 continues to move through theelectronic verification machine 500, the intermediate capacitive pick-uparea 892C and the intermediate capacitive pick-up area 892C′ function asexcitation and sensor capacitive pick-up areas, respectively, that arejoined by the portion 894J of the circuit element 880C. Similarly, theintermediate capacitive pick-up area 892C′ and the intermediatecapacitive pick-up area 892C″, together with the portion 894K of theresistive element 880C form a U-shaped circuit element, and theintermediate capacitive pick-up area 892C″ and the terminal capacitivepick-up area 884C, together with the portion 894L of the resistiveelement 880C form a U-shaped circuit element. Each of the circuitelements 878 therefore serves as a linear array of U-shaped circuitelements that are defined by two adjacent capacitive pick-up areas,882A-C and 892A-C, 892A-C and 892A′-C′, 892A′-C′ and 892A″-C″, 892A″-C″,and 884A-C, and the associated portions 894A-L of the resistive elements880A-C. Thus, when a given indicia spot area 872A-L is removed to markthe card 860 and reveal the underlying play indicia 876A-L, only theU-shaped circuit element which is partially defined by the associatedportion 894A-L of the resistive element 880A-C is affected. For example,when the indicia spot area 872A is removed to reveal the underlying playindicia 876A as shown in FIG. 77, the only affected U-shaped circuitelement is the one that is defined by the terminal capacitive pick-uparea 882A, the intermediate capacitive pick-up area 892A and theassociated portion 894A of the resistive element 880A.

It should be kept in mind that a similar result can be achieved if thecard is printed with a plurality of separate U-shaped circuit elements,such as the data circuit elements 750A-B of the ticket 700. However, themethod of printing the circuit elements 878 has advantages over printingindividual U-shaped elements such as 750A-B in that much fewercapacitive pick-up areas are required for each data bit. Also, for thoseapplications where the play indicia 876A-L are not required, the sealcoat 898 can be omitted from the marker card 860.

X. A Data Card According to the Invention

FIG. 90 shows a data card 922 which can be used with the electronicverification machine 500, shown in FIGS. 38-40. The data card 922includes circuit elements, generally denoted as 924, that are printeddirectly on a substrate 926. Each of the circuit elements 924 includestwo terminal capacitive pick-up areas, generally denoted as 928 and 930,and a data track, generally denoted as 932, that spans between the twoterminal capacitive pick-up areas 928 and 930. In addition, each of thecircuit elements 924 can include intermediate capacitive pick-up areas,generally denoted as 934, 936, and 938, that are positioned on the card922 intermediate the terminal capacitive pick-up areas 928 and 930 andare aligned with the terminal capacitive pick-up areas 928 and 930. Aswith the marker card 860, each pair of adjacent capacitive pick-upareas, for example, the capacitive pick-up area 928B and the capacitivepick-up area 934B, or the capacitive pick-up area 934B and thecapacitive pick-up area 936B, define partial U-Shaped circuit elementsthe remainder of which are defined by an associated portion 940A-L ofthe data tracks 932. The U-shaped circuit elements can in turn encodeeither a bit-off or “0” signal or a bit-on or “1” signal, depending onwhether or not the associated portions 940A-L of the data tracks 932contain conductive material. For example, the U-shaped circuit elementthat is defined by the capacitive pick-up areas 928A and 934A and theassociated portion 940A of the data track 932A encode a bit-off or “0”signal and the U-shaped circuit element that is defined by thecapacitive pick-up areas 928B and 934B and the associated portion 940Eof the data track 932B encodes a bit-on or “1” signal. Thus, readingfrom left to right, the first row of U-Shaped circuit elements encodes“011”, the second row of U-Shaped circuit elements encodes “110”, thethird row of U-shaped circuit elements encodes “100” and the fourth rowof U-shaped circuit elements encodes “111”. A suitable ink for printingthe circuit elements 924A-C for the data card 922 can be printed withthe ink that was previously described in Table 1.

FIG. 91 illustrates an alternative embodiment of a data card 942according to the invention. Like the data card 922, the data card 942includes circuit elements 924A-C. The main difference between the datacard 922 and the data card 942 is that the data card 942 includes arelease coat 944 that is printed on the substrate 926 so that therelease coat underlies the portions 940A-L of the data tracks 932A-C butdoes not underlie any of the capacitive pick-up areas 928A-C, 930A-C,934A-C, 936A-C, and 938A-C. As with the marker card 860, the releasecoat 944 can be printed on the substrate 926 either as discreet releasecoat layer portions 946A-F or as spaced-apart strips 948A-B. The circuitelements 924A-C are therefore printed on the data card 942 so thatinitially each of the data tracks 932A-C contains conductive material inall of the portions 940A-L of the data tracks 932A-C. After the datacard 942 is printed, specific portions 940A-L of the data tracks 932A-Care scratched-off to encode the desired binary data. For example theportion 940A of the resistive track 932A, the portion 940G of the datatrack 932B, and the portions 940J and 940K of the data track 932C havebeen removed subsequent to printing the data card 942. Thus, readingfrom left to right, the first row of U-Shaped circuit elements encodes“011”, the second row of U-Shaped circuit elements encodes “110” thethird row of U-shaped circuit elements encodes “100” and the fourth rowof U-shaped circuit elements encodes “111”. A suitable ink for printingthe circuit elements 924A-C for the data card 942 was previously givenin Table 3.

XI. A Laminated Document According to the Invention

FIG. 92. shows a laminated document 950 that can be used with theelectronic verification machine (shown in FIGS. 38-40). Laminateddocuments, such as the document 950, have a variety of uses includingprotecting an information document against excessive wear. One exampleof a laminated document, such as the document 950, is an identificationcard such as a driver's license where the information document is aphotograph. Laminated documents, such as identification cards, can bealtered, for example, by splitting the laminated document to remove theoriginal identification document and then substituting a fraudulentidentification document. The laminated document 905 helps to preventsuch fraudulent misuse. As shown in FIG. 92, the document 950 includes afirst laminate 952, a second laminate 954, and an information document956, such as a photograph. The laminated document 950 also includes twocircuit elements 958 and 960, each of which is secured to or printed onone of the laminates 952 and 954. FIG. 93 illustrates the first laminate952 which includes an upper surface 962 on which the circuit element 958is printed. The laminate 952 preferably is made from a durablenon-conductive material, such as plastic, that can be opaque and thathas a sheet resistivity greater than 10⁸ Ω/□. The outline of theinformation document 956 is shown in phantom for reference. The circuitelement 958 includes two capacitive pick-up areas 964 and 966. Thecapacitive pick-up area 966 is shaped and positioned on the uppersurface 962 of the laminate 952 so that the capacitive pick-up area 966capacitively couples with the excitation plate 576 of the sensor array502 in the electronic verification machine 500. The capacitive pick-uparea 964 is shaped and positioned on the upper surface 962 of thelaminate 952 so that the capacitive pick-up area 964 capacitivelycouples with one of the sensor plates 574 of the sensor array 502. Thecircuit element 952 further includes a resistive element 968 that isconnected to and extends between the capacitive pick-up areas 964 and966 so that at least a portion 970 of the resistive element 968underlies the information document 956 in the laminated document 950.

FIG. 94 illustrates the second laminate 954 which includes a lowersurface 972 on which the circuit element 960 is printed. The laminate954 preferably is made from a transparent material, such as plastic,that has a sheet resistivity greater than 10⁸ Ω/□. The outline of theinformation document 956 is shown in phantom for reference. The circuitelement 960 includes two capacitive pick-up areas 974 and 976. Thecapacitive pick-up area 976 is shaped and positioned on the lowersurface 972 of the laminate 954 so that the capacitive pick-up area 976capacitively couples with the excitation plate 576 of the sensor array502 in the electronic verification machine 500. The capacitive pick-uparea 974 is shaped and positioned on the lower surface 972 of thelaminate 954 so that the capacitive pick-up area 974 capacitivelycouples with one of the sensor plates 574 of the sensor array 502. Thecircuit element 954 further includes a resistive element 978 that isconnected to and extends between the capacitive pick-up areas 974 and976 so that at least a portion 980 of the resistive element 978 overlaysthe information document 956 in the laminated document 950. A suitableink for printing the circuit elements 968 and 069 was presentlypreviously in Table 1.

In making the finished laminated document 950 shown in FIG. 92, theinformation document 956, shown in FIG. 95, is positioned on the firstlaminate 952 so that the portion 970 of the resistive element 960underlies the information document 950. The second laminate 954 is theninverted, relative to its configuration in FIG. 94, so that the lowersurface 972 of the second laminate 954 is adjacent the upper surface 962of the first laminate 952. The second laminate 954 is also aligned withthe information document 956 so that the portion 980 of the circuitelement 960 overlies the information document 956. The two laminates 952and 954 are then bonded together to form the laminated document 950.Thereafter, if an attempt is made to split the laminated document 950and remove the information document 956, one or both of the resistiveelements 968 and 978 will be damaged or broken. The resulting change inthe electrical signature of the affected circuit element 958 or 960 canthen be detected by the sensor array 502 of the electronic verificationmachine 500.

XII. A Third Electronic Verification Machine

A. Components

A third and preferred embodiment of an electronic verification machine1000 according to the invention is shown in FIG. 96. The electronicverification machine 1000 includes a frame structure 1002 (shown in FIG.97) which is enclosed within a housing 1004 that includes a coversection 1006, a bottom section 1008, and a front section 1010. Althoughthe exact configuration of the exterior of the electronic verificationmachine 1000 can vary, the exterior of the electronic verificationmachine 1000 preferably includes a display panel 1012, a user interface1014, and a document interface 1016, all of which are positioned alongthe cover section 1006. The display panel 1012 can display instructions,such as “Insert Ticket” and can also display the results of documentvalidation and verification testing. The display panel 1012 preferablyconsists of a commercially available display unit, such as a liquidcrystal display, a gas discharge display, or a light emitting diode(LED) display. The user interface 1014 includes a numeric keypad, showngenerally as 1018, and function keys, shown generally as 1020. Theoperator can use the user interface 1014 to manually enter data from thedocument into the electronic verification machine 1000. The documentinterface 1016 includes a slot 1022 into which the document to be testedis inserted. In the preferred embodiment, the document interface 1016also includes an exit slot 1024 from which the document being testedexits the electronic verification machine 1000. In addition, theelectronic verification machine 1000 preferably includes a door 1026located on the front section 1010 of the housing 1004. The door 1026provides access to the document pathway and can be used to clear thepathway should the document become jammed within the electronicverification machine 1000. The door 1026 also provides access to amirror 1028 (shown in phantom) that is positioned along the innersurface of the door 1026. As explained below, the mirror 1028 can beused to read certain kinds of data printed on the document. The door1026 and associated front section 1010 also include a door positionsensor 1029. Indicator lights 1030 located on the front section 1010 canbe used to indicate that the door 1026 is open or jammed, that adocument is jammed within the document channel 1038, or that theelectronic verification machine 1000 is unable to scan a document.

FIG. 97 shows the electronic verification machine 1000 with the housing1004 removed. The frame structure 1002 includes a base portion 1032 anda front portion 1034 that is generally aligned with the front section1010 of the housing 1004 (as shown in FIG. 96). A sensor head 1036 issecured to the frame structure 1002 to form a channel 1038 intermediatethe front portion 1034 of the frame structure 1002 and the sensor head1036. The channel 1038 defines the document pathway through theelectronic verification machine 1000. In the preferred embodiment of theinvention, the sensor head 1036 is tensionably secured to the framestructure 1002 so that the document being tested is in intimate physicalcontact with a sensor array 1044 (shown in FIGS. 99 and 100) positionedon the sensor head 1036. The sensor head 1036 therefore includes hingepins 1040 that are rotatably mounted in hinge arms 1042 formed on thefront portion 1034 of the frame structure 1002. A tensioning guide 1046is located along the sensor head 1036, opposite the front portion 1034of the frame structure 1002 and is secured to the frame structure 1002by tensioning fasteners 1048. The tensioning guide 1046 is preferablyformed from a rigid material, such as metal, and the tensioningfasteners 1048 can be formed from any appropriate stretchable devices,such as springs. The tensioning guide 1046 helps to ensure that thedocument being tested maintains intimate physical contact with thesensor array 1044 while the hinge pins 1040 permit the sensor head 1036to pivot slightly so that the electronic verification machine 1000 canaccept documents of varying thickness. A ribbon connector 1050 extendsthrough an aperture 1052 (shown in FIG. 98) formed in the tensioningguide 1046 and operatively connects the sensor head 1036 to a mastercontrol processing board 1054 which is affixed to the frame structure1002.

The electronic verification machine 1000 also includes a pressure roller1056 which moves the document being tested through the document channel1038 and through the exit slot 1024 (shown in FIG. 96). The pressureroller 1056 is supported in the frame structure 1002 via a shaft 1055which also supports a pulley 1057. A stepper motor 1058 is alsosupported on the frame structure 1002 via a shaft 1059, on which is alsomounted a pulley 1060. A toothed belt 106I looped around the pressureroller pulley 1057 and the stepper motor pulley 1060 connects thepressure roller 1056 to the stepper motor 1058. As explained in moredetail below, the stepper motor 1058 is operatively connected to themaster control processing board 1054 and controls the rate at which thedocument being tested is moved through the document channel 1038. Inaddition, edge detectors 1062 and 1064 (shown in FIG. 98), which areoperatively connected to the master control processing board 1054 bysets of lines 1066 and 1068 and by ribbon connector 1050, provideinformation about the position of the document being tested within thedocument channel 1038. The electronic verification machine 1000 furtherincludes a bar code reader 1070 which is secured to the frame structure1002 and is operatively connected to the master control processing board1054 via connector lines 1072.

FIG. 98, which is a partially cut-away exploded side perspective view ofthe electronic verification machine 1000, shows the relationship amongthe cover section 1006 of the housing 1004, the front portion 1034 ofthe frame structure 1002, the sensor head 1036, the tensioning guide1046, and the front section 1010 of the housing 1004 in more detail. Theuser display panel 1012 and the user interface 1014, located along thecover portion 1006, are operatively connected to the master controlprocessing board 1054 via a ribbon connector 1015. When the electronicverification machine 1000 is fully assembled, the ticket slot 1022formed in the cover portion 1006 is aligned with the document channel1038 (shown in FIG. 97) which is formed between the front portion 1034of the frame structure 1002 and the sensor head 1036. The pressureroller 1056 extends through an aperture 1074 formed in the front portion1034 of the frame structure 1002. Consequently, the pressure roller 1056contacts the document being tested and moves the document through thedocument channel 1038 (shown in FIG. 97). In the preferred embodiment,the edge detectors 1062 and 1064 consists of two light emitting diodes1076 and 1078 and two phototransistors 1080 and 1082. The light emittingdiodes 1076 and 1078 are positioned along the front portion 1034 of theframe structure 1002 on opposite sides of the pressure roller 1056. Thephototransistors 1080 and 1082 are positioned along the sensor head 1036on opposite sides of a sensor array circuit board 1084 which is securedto the sensor head 1036. The phototransistors 1080 and 1082 on thesensor head 1036 are aligned with the light emitting diodes 1076 and1078 on the frame structure 1002 to form the edge detectors 1062 and1064. The first edge detector 1062 is used to indicate that a documenthas been inserted into the electronic verification machine 1000. Thesecond edge detector 1064 is used to obtain precise document positioninformation. The first edge detector 1062 and the second edge detector1064 are spaced-apart by a pre-determined distance which, in thepreferred embodiment, is about 1.48 inches. In addition, the second edgedetector 1064 is located at a pre-determined distance, preferably 0.73inches, below the tangent point of the pressure roller 1056.

The electronic verification machine 1000 also includes a window 1086formed along the front portion 1034 of the frame structure 1002. Thewindow 1086 is aligned with both the bar code reader 1070 and the mirror1028 located along the front section 1010 of the housing 1004. Together,the mirror 1028 and the window 1086 can be used with the bar code reader1070 to read bar codes that are printed on the front of the documentbeing tested. Alternatively, bar codes that are printed on the back ofthe document being tested can be read by the bar code reader 1070 andthe window 1086 alone. As noted earlier, the electronic verificationmachine 1000 can also include indicator lights 1030 located on the frontsection 1010 of the housing 1004. The indicator lights 1030 areoperatively connected to the door position sensor 1029 (shown inphantom) which also is located on the front section 1010 and which, inthe preferred embodiment, includes a light emitting diode and aphototransistor. The door position sensor 1029 and the indicator lights1030 are operatively connected to the master control processing board1054 by lines 1090 and 1092, respectively.

FIG. 99 is a block diagram of the relationship among the majorcomponents of the electronic verification machine 1000. The sensor head1036 is connected to the master control processing board 1054 by theribbon connector 1050. The light emitting diodes 1076 and 1078 whichform parts of the edge detectors 1062 and 1064, respectively, areconnected to the master control processing board 1054 by the lines 1066and 1068, respectively. The door position sensor 1029 is connected tothe master control processing board 1054 by the line 1090, while theindicator lights 1030 are operatively connected to the master controlprocessing board 1054 by the line 1092. A line 1094 operatively connectsthe stepper motor 1058 to the master control processing board 1054. Thelines 1072 operatively connect the bar code reader 1070 to the mastercontrol processing board 1054. The user interface 1014 is operativelyconnected to the master control processing board 1054 by the ribbonconnector 1015. The electronic verification machine also includes astigmatization circuit 1096 which is used in conjunction with the sensorarray 1044 and the master control processing board 1054 to stigmatize adocument being tested once its electrical signature has been measured.The stigmatization circuit 1096 is operatively connected to the sensorarray 1044 by lines 1098 and to the master control processing board 1054by lines 1100.

In the preferred embodiment of the invention, master control processingboard 1054 includes two microcontrollers, a support microcontroller 1102and a primary microcontroller 1104. The support microcontroller 1102 isused in controlling all low-level device interfaces, such as the sensorarray 1044, the stigmatization circuit 1096, the edge detectors 1062 and1064, the door position sensor 1029, the indicator lights 1030, the userinterface 1014, the bar code reader 1070 and the stepper motor 1058. Aset of lines 1106-1110 provides signal inputs and outputs to the supportmicrocontroller 1102. In the preferred embodiment of the invention, thesupport microcontroller 1102 is a Motorola MC68HC16 processor whichincorporates a 16 bit central processing unit, a single chip integrationmodule, a multi-channel communications interface, a general purposetimer and a time processing unit. The support microcontroller alsoincludes an 8 to 10 bit analog-to-digital (A/D) converter 1112 andmemory 1114. The memory 1114 of the support microcontroller 1102preferably includes 48 Kbytes of Programmable Read Only Memory (PROM)and 65 Kbytes of Static Random Access Memory (SRAM). The bar code reader1070 is connected to the support microcontroller 1102 by a standardbidirectional UART port operating at 9600 Baud. The internal timers ofthe support microcontroller 1102 are used to control the stepper motor1058. The edge detectors 1062 and 1064 are interfaced to the supportmicrocontroller as standard Transistor-Transistor Logic (TTL) signals.

The primary microcontroller 1104 is used to process the electricalsignature of the document being tested in order to verify that thedocument is authentic. In the preferred embodiment of the invention, theprimary microcontroller 1104 preferably is a 32 bit Elan SC410A whichoperates at an internal clock speed of 66 MHz. The primarymicrocontroller 1104 also includes memory 1116 which, in the preferredembodiment consists of 4-8 Mbytes of Dynamic Random Access Memory(DRAM), 2-4 Mbytes of flash memory, and 512 Kbytes to 1 Mbyte of SRAMsupported by a back up battery. In the preferred embodiment of theinvention, the primary microcontroller 1104 includes a gluelessburst-mode interface that allows the flash memory to be partitioned into various sectors, e.g., operating system, operational softwareversionA, operational software version B, etc. The primarymicrocontroller 1104 is connected to the support microcontroller 1102 bya high speed parallel interface 1118. A parallel interface 1120 connectsthe primary microcontroller 1104 to a Dual Universal AsynchronousReceiver-Transmitter (DUART) 1122 which is also connected by a RS-232serial digital interface 1124 to a modem 1126. In the preferredembodiment of the invention, the modem 1126 is a 14.4 kbps Rockwellmodem. The modem 1126 is used to provide communications between theelectronic verification machine 1000 and a central site computer, suchas the computer 223 (shown in FIG. 17).

As mentioned earlier, the support microcontroller 1102 is used for alllow level device interfaces. Consequently, the primary microcontroller1104 is used only for high level functionality such as comparing themeasured electrical signature to a predetermined game signature map suchas shown in FIG. 44. In addition, the primary microcontroller 1104communicates with the central site computer 223 to obtain game specificinformation such as the game signature map 632, and to determine theredemption value of high level probability game lottery tickets, such asthe ticket 700. To maximize communications flexibility with the centralsite computer, the electronic verification machine can also be equippedwith an optional Motorola MC68302 communications processor (not shown).This communications processor would then be used to handle all low-levelcommunications protocols, thereby allowing the primary microcontroller1104 to focus exclusively on high-level ticket/user functionality.

FIG. 100 is a top plan view of the sensor head 1036 and shows the sensorarray 1044 in more detail. The sensor head 1036 includes thephototransistors 1080 and 1082 that form parts of the edge detectors1062 and 1064 (shown in FIG. 98) and the sensor array circuit board 1084of which the sensor array 1044 forms a part. In the preferredembodiment, the sensor array circuit board 1084 is secured to a sensorhead housing 1128 which also carries the phototransistors 1080 and 1082.Due to the intimate physical contact between the document being testedand the sensor head 1036, if not protected the phototransistors 1080 and1082 can become dirty over time due to contact with the document beingtested. Consequently, in the preferred embodiment of the invention, thephototransistors 1080 and 1082 are embedded within and protected by thesensor head housing 1128 which is formed from a plastic that istransparent in the infrared region. In the preferred embodiment, a clearAcrylic with a 94-V0 flame rating is used to form the sensor headhousing 1128.

The sensor array 1044 includes an elongated excitation plate 1130,thirteen sensor plates 1132A-1132M, and a fuse excitation pad 1134. Itshould be noted that, in an embodiment of the invention that does notinclude stigmatization, the fuse excitation pad 1134 can be replacedwith a sensor plate to provide fourteen document sensor channels. Thevertical dimension of each of the sensor plates 1132A-1132M preferablyis 0.1 inches and the horizontal dimension of each of the sensor plates1132A-1132M preferably is 0.1 inches. The vertical dimension of theexcitation plate 1130, which preferably is located about 0.05 inchesfrom the sensor plates 1132A-1132M, preferably is 0.1 inches. Thehorizontal dimension of the fuse excitation pad 1130 preferably is about0.1 inches and the vertical dimension preferably is about 0.26 inches.The sensor array 1044 can also include a thin ground strap 1136positioned intermediate the excitation plate 1130 and the sensor plates1132A-1132M. Because of the close proximity of the excitation plate 1130and the sensor plates 1132A-1132M, the excitation signal can jumpbetween the excitation plate 1130 and the sensor plates 1132A-1132M,resulting in an inaccurate electrical signature. The ground strap 1136behaves as an “electrical fence” and prevents signal jumping from theexcitation plate 1130 to the sensor plates 1132A-1132M. The spacingbetween any two adjacent sensor plates 1132A-1132M, such as the sensorplates 1132B and 1132C, is chosen to minimize stray capacitance betweenthe sensor plates 1132A-1132M. The inter-sensor plate spacing should beabout twice the horizontal dimension of the sensor plates 1132A-1132M.In the preferred embodiment of the invention, the spacing between anytwo adjacent sensor plates 1132A-1132M, such as the sensor plates 1132Band 1132C, is about 0.18 inches. The horizontal dimension of theexcitation plate 1130 is chosen so that the excitation plate 1130 spansthe distance of the thirteen sensor plates 1132A-1132M. In the preferredembodiment of the invention, the horizontal dimension of the excitationplate 1130 therefore is about 3.46 inches.

The excitation plate 1130, the sensor plates 1132A-1132M, the fuseexcitation pad 1134, and the ground strap 1136 preferably are made froma highly conductive material, such as copper. However, it has been foundthat over time the sensor array 1044 can become worn due to the closephysical contact of the document being tested. Consequently, in thepreferred embodiment of the invention, the excitation plate 1130, thesensor plates 1132A-1132M, the fuse excitation pad 1134, and the groundstrap 1136 are initially formed as a three-part layer consisting ofcopper, covered by nickel, covered by a thin layer of gold. The nickelprotects the copper surface and protects the sensor array 1044 fromundue wear and tear. The thin gold layer allows other parts of thesensor array circuit to be soldered onto the sensor array circuit board1084. Over time, the gold layer covering the sensor array elements 1130,1132A-1132M, 1134, and 1136 wears away leaving only the nickel-coatedcopper layer. The thin gold layer over the sensor array elements 1130,1132A-1132M, 1134, and 1136 thus serves as a sacrificial mask while thethin gold layer on other portions of the sensor array circuit board 1084permits soldering of other sensor head components.

It has also been found that, because of the close physical contactbetween the sensor array 1044 and the document being tested,irregularities along the top surface 1138 of the sensor array circuitboard 1084 can cause the document to become jammed in the documentchannel 1038 (shown in FIG. 97). Consequently, care must be taken infabricating the sensor array circuit board 1084 to ensure that thesensor array elements 1130, 1132A-1132M, 1134, and 1136 are essentiallyflush with the top surface 1138 of the sensor array circuit board 1084.Preferably, the sensor array elements 1130, 1132A-1132M, 1134, and 1136project less than 0.00006 inches from the top surface 1138. Ifnecessary, a non-conductive epoxy film can be applied to the top surface1138 to achieve this goal.

The general operation of the electronic verification 1000 to measure theelectrical signature and other verification data of a document will nowbe explained with reference to the ticket 700, shown in FIG. 49.Referring now to FIGS. 96-100, the document to be tested, such as theticket 700, is placed in the document ticket slot 1022 so that the back822 of the ticket 700 faces the front portion 1034 of the framestructure 1002. The ticket 700 drops into the document channel 1038until it reaches the top of the pressure roller 1056. At this point, thefirst edge detector 1062 signals the support microcontroller 1102 thatthe ticket 700 is present in the document channel 1038. Consequently,the support microcontroller 1102 provides a first pulse rate to thestepper motor 1058 which rotates the pressure roller 1056 at a firstrate to move the ticket 700 down the ticket channel 1038 past the sensorhead 1036. In the preferred embodiment of the invention, the steppermotor 1058 advances the ticket 700 in discrete steps of about 0.02inches per step. The first pulse rate supplied by the supportmicrocontroller 1102 preferably is 300 steps per second. Thus, thepressure roller 1056 initially moves the ticket 700 in the documentchannel 1038 at a rate of about six inches per second. As soon as thestepper motor 1058 has been activated, the support microcontroller 1102activates the sensor array circuit board 1084 so that the sensor array1044 measures the electrical signature of the ticket 700. The electronicverification machine 1000 measures the electrical signature of thedocument being tested, such as the ticket 700, by capacitively couplingan excitation signal from the triangular waveform generator 510 (shownin FIGS. 40, 41, and 101) to the document via the excitation plate 1130.Since there are thirteen sensor plates 1132A-1132M, the sensor array1044 provides thirteen sensed electrical signature values for each stepof the stepper motor 1058. The thirteen sensed electrical values areforwarded to associated amplifiers and boosters. The processed signal isthen sampled by the 8-bit A/D converter 1112. The 8-bit values of thesampled signals are then passed to the primary microcontroller 1104 foranalysis.

As the stepper motor 1058 moves the ticket 700 through the documentchannel 1038 at the first pulse rate, the leading edge of the ticket 700eventually passes the second edge detector 1064 and thereby activatesthe second edge detector 1064. The stepper motor 1058 then continues tomove the ticket 700 through the document channel 1038 via the pressureroller 1056 until the support microcontroller 1102 determines that thebar code 730, which is printed on the ticket identification portion 708(shown in FIG. 49) of the ticket 700, is in position for reading by thebar code reader 1070. The bar code 730 is printed on the ticket 700 at apredetermined position, relative to the leading and following edges ofthe ticket 700. Since the ticket 700 moves through the document channel1038 at a pre-determined rate, in this case a rate of 0.02 inches perstep, the location of the leading edge of the ticket 700 involves simplycounting the number of stepper motor steps which have occurred since thesecond edge detector 1064 was activated. Once the ticket 700 is inposition for the bar code reader 1070 to read the bar code 730, thesupport microcontroller 1102 provides a second pulse rate to the steppermotor 1058 so that the ticket 700 moves at a second predetermined ratewhile the bar code 730 is being read. The bar code reader 1070 operatesat a pre-determined rate which, in the preferred embodiment of theinvention is thirty Hertz. Consequently, the rate at which the ticket700 moves past the bar code reader 1070 must be slower than the initialrate at which the ticket 700 moves through the document channel 1038 toensure an accurate reading of the bar code 730. Therefore, in thepreferred embodiment of the invention, the second pulse rate provided bythe support microcontroller 1102 is 15 steps per second so that the barcode 730 on the ticket 700 moves past the fixed bar code reader 1070 ata rate of 0.3 inches per second. If the bar code reader 1070 is not ableto read the bar code 730, the stepper motor 1058 continues to move theticket 700 at the second rate until the support microcontroller 1102determines that the bar code 730 has moved completely past the bar codereader 1070. Since the bar code 730 has a predetermined height,determining that the bar code 730 has moved past the bar code reader1070 involves counting the stepper motor steps which have occurred sincethe support microcontroller 1102 initiated the second pulse rate. If thebar code reader 1070 still has not been able to read the bar code 730,the support microcontroller 1102 stops the stepper motor 1058 and sendsa reverse pulse rate to the stepper motor 1058 so that the ticket 700 ismoved back out through the document slot 1022, thereby alerting theoperator that the bar code 730 has not been read.

Once the bar code 730 is read by the bar code reader 1070, the supportmicrocontroller 1102 again sends the first pulse rate to the steppermotor 1070 to move the ticket 700 through the document channel 1038 atthe first rate until the following edge of the ticket 700 passes thefirst edge detector 1062 and thereby inactivates the first edge detector1062. The support microcontroller 1102 then calculates the number ofadditional stepper motor steps needed to move the ticket 700 past thesensor head, based on the pre-determined distance between the first edgedetector 1062 and the second edge detector 1054. The stepper motor 1070then continues to move the ticket 700 at the first predetermined ratefor the calculated number of stepper motor steps needed for the ticket700 to clear the sensor head 1102. At this point, the supportmicrocontroller 1102 deactivates both the stepper motor 1058 and thesensor head 1036. The measured electrical signature value of thedocument being tested is then transmitted the primary microcontroller1104 for verification analysis.

In addition to providing document position information to the supportmicrocontroller 1102 while the ticket 700 is being read by theelectronic verification machine 1000, the edge detectors 1062 and 1064also provide information which controls how the support microcontroller1102 responds if the ticket 700 becomes jammed in the electronicverification machine 1000. For example, the operator may inadvertentlyplace an improperly sized document into the electronic verificationmachine 1000. If the document is too short, the first edge detector 1062can become deactivated before the leading edge of the document passesthe second edge detector 1064 and the document can become jammed in thedocument channel 1038. The support microcontroller 1102 uses thepre-determined distance between the first edge detector 1062 and thesecond edge detector 1064 to determine if a short ticket has beeninserted into the electronic verification machine 1000. The number ofstepper motor pulses needed to move the leading edge of a document fromthe first edge detector 1062 to the second edge detector 1064 ispre-determined by the distance between the first edge detector 1062 andthe second edge detector 1064 and by the size of each stepper motorstep. If the first edge detector 1062 is deactivated before the secondedge detector 1064 is activated, the document must be less than 1.478inches long. Once the leading edge of the document activates the secondedge detector 1064, 0.73 inches of the ticket must have moved from thetangent point of the pressure roller 1056 to the second edge detector1064, leaving at most 0.75 inches of the ticket to be moved through thedocument channel 1038 past the second edge detector. As previouslystated, the first predetermined pulse rate moves the document at 0.02inches per stepper motor step. Consequently, the support microcontroller1102 continues to provide the first pulse rate to the stepper motor foran 38 additional stepper motor steps, at which time the document shouldbe past the second edge detector 1064 and free of the document channel1038.

The edge detectors 1062 and 1064 can also be used to provide data thathelps to verify the authenticity of the document being tested. Forexample, when the document being tested is a probability game lotteryticket, such as the ticket 700, the size of the ticket 700 can be usedto help determine if the ticket is authentic. Once the ticket has passedcompletely though the document channel 108, the size of the ticket canbe determined by counting the number of stepper motor steps which haveoccurred between the activation and deactivation of the second edgedetector 1064. The measured value for the size of the ticket 700 canthen be compared to a pre-determined value for the size of the ticket700 to provide an additional parameter by which the authenticity of theticket 700 can be tested.

B. Determining the Electrical Signature

One of the objects of the electronic verification machine 1000 is todetermine the electrical signature of the document being tested. Whenthe document being tested consists of a probability game ticket, such asthe ticket 700 (shown in FIG. 49), the electrical signature consists ofa two-dimensional array or grid which represents the location and amountof conductive material found on the document. The sensor array 1044 ofthe electronic verification machine 1000 is used to scan the playingfield portion 706 and the ticket identification portion 708 of theticket 700 to determine the amount and location of conductive materialsand to generate a scanned data map or scratch map, such as that shown inFIG. 45. The primary electrical signature value that the sensor array1044 detects is the total capacitance of the excitation plate 1130 and agiven one of the sensor plates 1132A-1132M. In general, capacitance isdefined by Maxwell's equation:

C=K∈ ₀(A/T)

where K is the dielectric constant of the insulating material separatingthe conductive planes of the capacitor, A is the intersecting area ofthe conductive planes, T is the thickness of the insulating material and∈₀ is the permittivity of free space. When the sensor array 1044 iscapacitively coupled to the document being tested, such as the ticket700, the excitation plate 1130 and a given one of the sensor plates1132A-1132M, such as the sensor plate 1132A, function as two capacitorsC1 and C2 whose capacitance depends on the nature and amount ofconductive material on the portions of the ticket 700 which underlie theexcitation plate 1130 and the sensor plate 1132A.

A simplified partial circuit diagram of the capacitive coupling betweenthe sensor array 1044 and the document being tested, such as the ticket700, is shown in FIG. 101. C_(t1) represents the capacitance between theexcitation plate 1130 and the document being tested and C_(t2)represents the capacitance between the document and one of the sensorplates 1132A-1132M, such as the sensor plate 1132A. The portion of theticket 700 which is intermediate the excitation plate 1130 and thesensor plate 1132A functions as a resistor having a resistancerepresented by R_(t) and effectively connects in series the capacitorsC1 and C2 formed at the excitation plate 1130 and the sensor plate1132A, respectively. Consequently, the total coupling capacitanceC_(total) is the combined capacitances of C_(t1) and C_(t2). Themagnitudes of C_(t1) and C_(t2) depend on the nature and amount ofconductive material on the portions of the ticket 700 which underlie theexcitation plate 1130 and the sensor plate 1132A. Referring back toFIGS. 49-71, it will be recalled that the ticket 700 is printed inseveral different layers. One of the conductive layers printed on theticket 700, such the integrity circuit element 740 layer, the indiciacircuit elements 732A-732H layer, or the upper blocking layer 830,serves as the conducting plane in the ticket 700 which operates with theexcitation plate 1130 and the sensor plate 1132A to form the twocapacitors C1 and C2. The printed layers which lie between theexcitation plate 1130 and the conductive layer and which lie between thesensor plate 1132A and the conductive layer serve as the insulatingmedium whose thickness and dielectric constant affect the magnitudes ofC_(t1) and C_(t2). The particular conductive layer which forms theconducting plane in the ticket 700 varies depending on the portion ofthe ticket 700 which is capacitively coupled to the sensor array 1044,as do the particular layers which form the insulating medium.

The printing sequence described with reference to FIGS. 49-77 results inat least three general types of printed layer patterns on the ticketsubstrate 702, as shown in FIGS. 102A-104B. Referring to FIG. 102A, afirst printed layer pattern 1140 consists of the first opaque blockinglayer 794, the layer containing the integrity circuit element 740, themasking layer 818, the primer layer 820, and the layer containing thebar code 730. The first printed layer pattern 1140 is formed on theticket identity portion 708 (shown in FIG. 49) of the ticket 700. FIG.102B is a conceptual representation of the two capacitors which areformed when the excitation plate 1130 and the sensor plate 1132A arecapacitively coupled to a portion of the ticket 700 which contains thefirst printed layer pattern 1140. The capacitive pick-up area 744 of theintegrity circuit element 740 forms the conducting plane in the ticket700 that couples with the excitation plate 1130 to form the firstcapacitor. The capacitive pick-up area 742 of the integrity circuitelement 740 forms the conductive plane in the ticket 700 that coupleswith the sensor plate 1132A to form the second capacitor. The resistiveelement 746 of the integrity circuit element 740 functions as theresistor that connects the two capacitors in series. The masking layer818, the primer layer 820, and the layer containing the bar code 730serve as the insulating medium which is interposed between theexcitation plate 1130 and the capacitive pick-up area 744 and which isinterposed between the sensor plate 1132A and the capacitive pick-uparea 742. The thickness of the masking layer 818, the primer layer 820,and the layer containing the bar code 730 and the dielectric constant ofthe masking layer 818, the primer layer 820, and the layer containingthe bar code 730 affect the magnitude of the capacitances C_(t1) andC_(t2) formed at the excitation plate 1130 and the sensor plate 1132A.

A second printed layer pattern 1142, shown in FIG. 103A, consists of thefirst opaque blocking layer 794, the masking layer 818, the primer layer820, the seal coat layer 826, the upper blocking layer 830, and thescratch-off coating 846. The second printed layer pattern 1142 is formedon the playing field portion 706 of the ticket 700 in locations wherethere are no play indicia, such as the portion of the ticket 700 betweenthe play spot area 716B and the play spot area 716C (shown in FIG. 49).FIG. 103B is a conceptual representation of the two capacitors which areformed when the excitation plate 1130 and the sensor plate 1132A arecapacitively coupled to a portion of the ticket 700 which contains thesecond printed layer pattern 1142. The upper blocking layer 830 servesas both the conductive plane in the ticket 700 and the resistor whichconnects the two capacitors in series. The scratch-off coating 846 andany overprint graphics serve as the insulating medium interposed betweenthe excitation plate 1130 and the upper blocking layer 830 and which isinterposed between the sensor plate 1132A and the upper blocking layer830. Consequently, the thickness of the scratch-off coating 830 and anyoverprint graphics and the dielectric constant of the scratch-off layer830 and any overprint graphics affect the magnitude of the capacitancesC_(t1) and C_(t2) formed at the excitation plate 1130 and the sensorplate 1132A.

A third printed layer pattern 1144, shown in FIG. 104A, consists of theblocking layer 794, the masking layer 818, the primer layer 820, thelayer containing the play indicia 720A-720H , the seal coat layer 826,the release coat layer 828, the upper blocking layer 830, the layercontaining the indicia circuit elements 732A-732H , and the scratch-offcoating 846. The third printed layer pattern 1144 is formed on theplaying field 706 portion of the ticket 700 at each of the play spotareas 716A-716H . FIG. 104B is a conceptual representation of the twocapacitors which are formed when the excitation plate 1130 and thesensor plate 1132A are capacitively coupled to a portion of the ticket700 which contains the third printed layer pattern 1144. The capacitivepick-up area 736 of any given indicia circuit element 732A-732H formsthe conducting plane in the ticket 700 that couples with the excitationplate 1130 to form the first capacitor. The capacitive pick-up area 734of the given one of the indicia circuit elements 732A-732H forms theconducting plane in the ticket 700 that couples with the sensor plate1132A to form the second capacitor. The resistive element 738 of thegiven one of the indicia circuit elements 732A-732H serves as theresistor that connects the two capacitors in series. The scratch-offcoating 846 and any overprint graphics serve as the insulating mediuminterposed between the excitation plate 1130 and the capacitive pick-uparea 736 and which is interposed between the sensor plate 1132A and thecapacitive pick-up area 734. Consequently, the thickness of thescratch-off coating 830 and any overprint graphics and the dielectricconstant of the scratch-off layer 830 and any overprint graphics affectthe magnitude of the capacitances C_(t1) and C_(t2) formed at theexcitation plate 1130 and the sensor plate 1132A.

As stated earlier, there are thirteen sensed electrical values for eachstep of the stepper motor 1058. The stepper motor 1058 advances thedocument being tested, such as the ticket 700, in discreet steps of 0.02inches each. The number of scan rows for a given document, such as theticket 700, can be determined by the following equation:

Scan Rows=H/0.02 inches

where H is the height of the document in inches. The thirteen electricalvalues for each step of the stepper motor 1058 correspond to theC_(total) across each one of the thirteen sensor plates 1132A-1132M andthe excitation plate 1130. C_(total) between any given one of the sensorplates 1132A-1132M, such as the sensor plate 1132A, and the excitationplate 1130 in turn depends upon the nature of the printed layer pattern,such as the printed layer patterns 1140, 1142, and 1144, that underliethe sensor plate 1132A and the excitation plate 1130. Each step of thestepper motor 1058 yields thirteen more electrical values, each of whichcan be different due to differences in the printed layer patterns whichunderlie each of the thirteen sensor plates 1132A-1132M. The resultingelectrical signature is a two-dimensional array or grid, where thex-axis represents the 13 electrical values for each step of the steppermotor 1058 and the y-axis represents the position of the sensor array1044 in stepper motor steps. The two dimensional array constitutes ascanned data map, such as the scanned data map 634 shown in FIG. 45,which represents the location and amount of conductive material on thetested document.

When the document being tested is a probability game lottery ticket,such as the ticket 700, the scanned data map, such as the map 634 (FIG.45), is compared to a game signature map, such as the map 632 shown inFIG. 44, to determine the authenticity of the document. The electronicverification machine 1000 downloads the game signature map from thecentral site computer via the modem 1126 and stores the game signaturemap in the memory 1116 of the primary microcontroller 1104. Each gamesignature map contains a series of vectors that define information aboutthe sensed electrical values in a given area of the ticket 700. The areaof the vectors is defined as a channel number (x-axis) by stepper motorsteps (y-axis). The sensed electrical values are provided by the 8-bitA/D converter 1112 in the support microcontroller 1102. In the preferredembodiment of the invention, there are three general types of vectors: aLatex Vector, which corresponds to the electrical integrity of theprinted layer patterns, such as the patterns 1140, 1142, and 1144, onthe ticket 700; a Paper Vector, which is used to determine the thicknessof the paper stock of the ticket 700 and to sense an object pushing theLatex Sensor off the paper substrate; and a Ghost Vector, which is usedto provide protection against photocopies of the ticket 700.

The software program that compares the scanned data map, such as the map634 (FIG. 45) with its associated game signature map, such as the map632 (FIG. 44) is called Electronic Latex Validation Software or ELVIS.ELVIS is stored in the flash memory portion of the memory 1116 in theprimary microcontroller 1104. After the ticket 700 has been successfullyscanned by the electronic verification machine 1000, ELVIS is called toanalyze the scanned data map of the ticket 700. ELVIS begins byextracting the first three digits of the bar code to determine the gamenumber of the ticket 700. ELVIS uses the extracted game number to findthe associated game signature map in the SRAM portion of the memory 1116of the primary microcontroller 1104. If there is no game signature mapfor the extracted game number, ELVIS aborts processing the ticket 700and transmits a No Signature Map error message to the display panel1012. The operator is then prompted to manually enter the three-digitsecurity number of the ticket 700 via the numeric keypad 1018.

Once ELVIS has retrieved a game signature map that corresponds to thedocument being tested, such as the ticket 700, ELVIS then counts thetotal number of scan rows to determined the size of the ticket 700. Ifthe ticket is found to be too big or too small, ELVIS aborts processingthe ticket and transmits a Ticket Too Big/Small error message. However,if the size of the ticket 700 is acceptable, ELVIS then analyzes thethree vector types for the ticket 700. The testing criteria used byELVIS depends on the vector type. For Latex Vectors, Elvis first addsall latex vectors together to determine the total “Play area.” After thetotal “Play Area” is determined, ELVIS applies a minimum and maximumpixel count criteria to determine if the total “play area” is incompliance. For Paper and Ghost Vectors, ELVIS will reject the ticket700 if the testing criteria for either of these vectors is not met.ELVIS first analyses the Paper Vectors areas of the ticket 700 todetermine if the signals are acceptable. Assuming that there are noPaper Vector errors, ELVIS will sum all of the Latex Vectors todetermine the status of the printed layer patterns, such as the patterns1140, 1142, and 1144, within the play field portion 706 of the ticket700. If the Latex Vectors are found to be acceptable ELVIS examines theGhost Vectors of the ticket 700 to determine if some of the removablescratch-off coating 846 remains in any played portion of the ticket 700.If all of the above vector tests are passed, ELVIS concludes that theticket 700 is authentic and has been validly played.

C. Stigmatization

In addition to measuring the electronic signature of the document beingtested, the electronic verification machine 1000 also can stigmatize thedocument. As explained earlier in Section VI., stigmatization refers toa process by which a document, such as the ticket 700, which has alreadybeen tested by the electronic verification machine 1000 is “marked. ” Inthe case of game tickets, such as the ticket 700, stigmatizationprevents winning tickets from being presented multiple times to be paid.A successful stigmatization scheme has several attributes. Thestigmatization should be automatic: if human intervention is required tostigmatize the document errors can occur when the stigmatization is notdone correctly. The stigmatization should also be difficult tocircumvent. Preferably, the stigmatization equipment should requireminimum maintenance. In addition, the stigmatization preferably permitsmonitoring of tested documents so that attempts at fraudulent redemptioncan be detected. Consequently, it is desirable that the stigmatizationbe difficult to detect.

Currently accepted practices for stigmatizing a game ticket, such as theticket 700, include visually marking the ticket, for example by stampingthe ticket with the words “PAID VOID”. Alternatively, it is common forwinning tickets to be destroyed once they have been redeemed. However,since both of these stigmatization schemes require human intervention,the possibility exists that a winning ticket will not be stigmatizedcorrectly and can then be presented multiple times for payoff. Inaddition, these stigmatization schemes do not permit monitoring of paidtickets so that attempts at fraudulent redemption can be detected.Another accepted practice is to maintain a paid ticket file in a centralcomputer. Although such a scheme does not necessarily require humanintervention and cannot be easily detected, such a stigmatization schemerequires that the ticket redemption terminal maintains a constant linkwith the central computer and such on-line linkages can be quite costly.As mentioned previously in Section IV., another method for stigmatizinga ticket involves automatically colorizing at least a portion of theticket once it has been presented for redemption. For example, a portionof the document could be printed with an invisible ink that is thermallysensitive. Once the ticket is presented for redemption, power applied bythe ticket terminal could be used to generate sufficient heat to changethe color of the invisibly printed portion, thereby automaticallystigmatizing the ticket. This scheme, however, has severaldisadvantages. The stigmatization is not difficult to detect,consequently this stigmatization scheme does not permit monitoring ofpaid tickets so that attempts at fraudulent redemption can be detected.Moreover, since heat is used as the method for activating the invisibleink and stigmatizing the ticket, heat sources other than the lotteryterminal can inadvertently result in ticket stigmatization, for example,when the ticket is left in a closed car on a hot day.

Referring back to FIG. 100, the fuse excitation pad 1134, together withthe sensor pad 1132M of the sensor array 1044 in the electronicverification machine 1000 can be used to electronically stigmatize adocument, such as the ticket 700. The fuse excitation pad 1134 providesa high voltage excitation signal which is used to alter the state of aprinted circuit element on the document. An example of a printed circuitelement that can be electronically altered by the electronicverification machine 1000 is shown in FIG. 105, where the printedcircuit element is an electronic fuse junction or fuse 1146. Theelectronic fuse junction 1146 includes an excitation pick-up area 1148and a sensor pick-up area 1150 connected by a fuse link 1152. Asexplained in more detail below, the electronic verification machine 1000provides sufficient energy to the electronic fuse junction 1146 via thefuse excitation pad 1134 (shown in FIG. 100) to open the fuse link 1152between the excitation pick-up area 1148 and the sensor pick-up area1150. As described in detail below, direct measurement circuitry in theelectronic verification machine 1000 has the capability of checking thestate of the electronic fuse junction 1146. An open electronic fusejunction 1146, where the fuse link 1152 is not present, normallyindicates that the document has already been tested by the electronicverification machine 1000. On the other hand, a closed electronic fusejunction 1146 indicates that the document has not been previously testedby the electronic verification machine 1000.

An important feature of the electronic fuse junction 1146 is that itchanges its binary status, from closed to open, when the electronicverification machine 1000 applies an energy pulse via the fuseexcitation pad 1134. Therefore the composition and configuration of theelectronic fuse junction 1146 is selected such that the electronic fusejunction 1146 changes its binary status upon receipt of the energy pulserather than simply absorbing the energy pulse through, for example, heattransfer to the substrate or other materials on the document. It isdesirable to make the time duration of the energy pulse provided by theelectronic verification machine 1000 as short as possible, for example,on the order of 0.1 seconds. By the same token, to minimize heattransfer to the ambient surroundings the fuse link 1152 should be assmall as possible. In addition, the electronic fuse junction 1146,including the fuse link 1152, preferably is formed from a material thathas a reasonably high resistance so that the current flow through thefuse link 1152 will generate enough heat to break the conductive path.

When the electronic fuse junction 1146 is printed on probability gametickets, such as the ticket 700, there are additional attributes thatthe electronic fuse junction 1146 should have. For example, theelectronic fuse junction 1146 should be formed from a material that isnot hazardous to the environment or to humans. The electronic fusejunction 1146 also should be formed from a material that can be printedwith a Gravure, Offset, or Lithograph printing press. It is alsodesirable that the electronic fuse junction 1146 should be formed from amaterial which is already being used on the ticket 700, to avoid havingto add an additional printing station.

In one example, the electronic fuse junction 1146 is printed on thedocument using an ink that has a sheet resistivity in a range of fromabout 8 MΩ/□ to about 2.4 KΩ/□. Preferably, the ink used to print theelectronic fuse junction 1146 has a sheet resistivity on the order of2.4 KΩ/□. Along with the above discussed criteria, the dimensions of thefuse link 1152 are determined by a number of additional factors,including by the printing press resolution, the characteristics of theink used to print the electronic fuse junction 1146, the dimensions ofthe sensor plates 1132A-1132M in the sensor array 1044, and thecharacteristics of the substrate on which the electronic binary junction1146 is printed. In the example of the electronic fuse junction 1146printed on a probability game ticket, such as the ticket 700, thevertical dimension of the excitation pick-up area 1148 preferably isabout 0.24 inches, as is the vertical dimension of the sensor pick-uparea 1150. The horizontal dimension of the excitation pick-up area 1148preferably is about 0.10 inches, as is the horizontal dimension of thesensor pick-up area 1150. The vertical dimension of the fuse link 1152preferably is about 0.02 inches and the horizontal dimension of the fuselink 1152 preferably is about 0.05 inches. In addition, when theelectronic fuse junction 1146 is printed on a probability game ticket,such as the ticket 700, the electronic fuse junction 1146 can be printedon the ticket 700 with the same ink used to print the play indiciacircuit elements 732A-732 H (shown in FIG. 50). Therefore, an additionalprinting station is not needed to print the electronic fuse junction1146 on the ticket 700. When the electronic fuse junction 1146 isprinted with an ink that has a sheet resistivity of 2.4 KΩ/□ and has theaforementioned preferred dimension the fuse link 1152 has a resistancebetween 6 KΩ and 16 KΩ that opens reliably with the application of 0.1joules of energy expended in 0.1 second or less. It should also bepointed out that the electronic fuse junction 1146 can be printed withthe same ink used to print the circuit elements on the probability gameticket 700 or with the upper conductive black ink on a conventionallottery ticket.

The functional block diagram of FIG. 106 illustrates the stigmatizationcircuit 1096 that can be used to stigmatize a document such as theprobability ticket 700 having the electronic fuse junction 1146 of thetype shown in FIG. 105. As indicated above, it has been found that theapplication of 0.1 joules of energy to the electronic fuse junction 1146in approximately 0.01 seconds is enough to reliably open the fuse link1152. To expend 0.1 joules in 0.01 seconds requires 10 watts of averagepower. Power in a resistor is equal to the product of the resistance andthe square of the current through it. For a 16,000Ω resistor such as thefuse link 1152, the required current is:

({fraction (10/16000)})^(½)=25 mA

The voltage across a resistor is equal to the product of the resistanceand the current through it. In this example, the required voltage isthen:

 16000×0.025=400 volts

Thus it is possible to open a 16 KΩ fuse junction by applying 400 voltsDC to the junction. Most 10-watt, 400-volt supplies, however, are largeand expensive. However, storing the energy in a capacitor, such as acapacitor C1 as shown in FIG. 106, over a relatively long time period,at a relatively low charging rate, and discharging the capacitor intothe electronic fuse junction 1146 quickly can substantially reduce thesize and cost of the supply. The energy stored in a capacitor is equalto:

Energy stored in cap.=½CE² joules

Solving for C,

C=(2E)/V ²

With E=0.1 joules and V=400 volts, C_(min)=1.25 μF. Since 1 μFcapacitors are more available than 1.25 μF capacitors, the above formulasuggests the use of a voltage V of at least 470 volts. With a voltage Vof 500 volts the total capacitor energy will be 0.125 joules. In thiscase, it will take approximately 13 ms to apply 0.1 joules of energyinto the fuse link 1152 which is significantly below the desired 100 msindicated above.

It is possible to provide a 500 voltage supply that runs continuously ora voltage supply that turns on when the leading edge of a document, suchas the ticket 700 passes the first edge detector 1062. The advantage tohaving the voltage supply constantly operating is that the electronicfuse junction 1146 could be located anywhere on the ticket 700,including the leading edge. On the other hand, if the voltage supply isoff until needed, the electronic binary junction 1146 should be locatednear the end of the ticket to allow the storage capacitor time to becharged. Assuming the tickets 700 are fed into the machine 1000 oneafter the other, the supply should be able to recover in the timerequired to process a 2-inch long ticket. Given that the stepper motormoves the ticket 700 at 0.02-inch per step at approximately 200 stepsper second, 0.5 seconds is available to charge the capacitor C1. Wherethe capacitor C1 is charged with a constant current and the actualvalues are V equal to 500 volts and C1 equal to 1 μF, total capacitorenergy will be 0.125 joules. Approximately 13 ms are required to dump0.1 joules into the 16,000Ω resistor 1152. This time is well below 100ms. Also since:

I=C(dv/dt)

I=(0.5)(1.0×10⁻⁶)/0.5=1 mA

The maximum output power from the supply is thus:

P=IV

P=500×0.001=0.5 watts

which is 20 times smaller than the 10-watt power supply mentioned above.

It should be understood that voltage converter topology presents avariety of choices. It is possible to use a push-pull converter, boostconverter, or flyback converter. In this case, there is no particularadvantage to transformer isolation and the output power is low enough tomake push-pull unnecessary. In order to reduce the cost of the voltagesupply, a simple boost power supply using a Texas Instruments (TI) TL497controller 1154, an off-the-shelf inductor, and 1 μF storage capacitorC1 are used in the preferred embodiment of the invention shown in FIG.106. The supply 1154 normally will require 0.3 seconds to produce 500volts on the capacitor C1.

Operation of the stigmatization circuit 1096 shown in FIG. 106 will nowbe described in connection with the operation of the electronicverification machine 1000. The supply 1154 is activated by a signal(from the support microcontroller 1102) on an inhibit line 1156 whichconverts a 12 volt DC voltage on a line 1158 from the system powersupply (not shown) to a 500 volt voltage on an input line 1160 to thecapacitor C1. The electronic fuse junction 1146 is moved by the steppermotor 1058 into position between the fuse excitation plate 1134 and thesensor pad 1132M. A voltage divider including a resistor R3 and the fuselink 1152 along with a diode D1 respond to a 5 volt signal on a line1162, from the system power supply (not shown), to apply a voltage on alink monitor line 1164 which in turn is input to an analog to digitalconverter (not shown) on the support microcontroller 1102. In the eventthat the fuse link 1152 is open, indicating that the ticket 700 mighthave already been stigmatized, a voltage of 5 volts will appear on thelink monitor line 1164. On the other hand, if the fuse link 1152 isstill present and ignoring the resistance in the fuse link 1152 and theresistor R3, a small voltage, for example 0.6 volts will appear on thelink monitor line 1164 due to the resistance in the diode D1 and a diodeD2. However, if the resistor R3 has a value equal to the value of thefuse link 1152 resistance, for example 16,000 KΩ, then the voltage onthe link monitor line 1164 will be about 2.8 volts. One advantage of theinvention is that by printing the fuse link 1152 with a known value, itis possible to significantly reduce the possibility of counterfeits byin effect measuring the resistance value of the fuse link 1152.

In one embodiment of the invention, once the value of the resistance ofthe fuse link 1152 is determined, the voltage of the output of the powersupply 1154 can be measured using a voltage divider including a pair ofresistors R1 and R2. The output of this voltage divider is applied overa high voltage monitor line 1166 to the analog to digital converter (notshown) on the support microcontroller 1102. In this manner it ispossible for the support microcontroller 1102 to determine if there issufficient charge on the capacitor C1 to blow the fuse link 1152. Whenthe voltage on the capacitor C1 has reached a predetermined value, suchas 470 volts, this voltage is applied to the fuse link 1152 via a switchSW1 and over the fuse excitation plate 1134 and the sensor pad 1132M.The switch SW1 can be a field effect transistor under control of thesupport microcontroller 1102 via a line 1166. It should be noted thatthe diode D1 serves to protect the link monitor line 1164 from the highvoltage on the capacitor C1. Also, in this circuit 1096, the diode D2prevents the current in the fuse link 1152 from pulling the pad 1132M tomore than 0.7 volts above ground.

One of the advantages of the circuit 1096 shown in FIG. 106 is that theplate 1132M can be used as both a sensor plate for sensing the variouscriteria in the ticket 700 as described above and as ground plate forstigmatizing the ticket 700. Here a switch SW2, which also can be afield effect transistor, is switched on at the same time the switch SW1is closed in response to the stigmatization signal on the line 1166.This prevents the current in the fuse link 1152 from returning to thesensor excitation circuit.

In the preferred embodiment, after the stigmatization voltage has beenapplied from capacitor C1 to the electronic fuse junction 1146, theswitches SW1 and SW2 are opened and the support microprocessor 1102measures the voltage on the link monitor line 1164. If the voltage onthis line is 5 volts, indicating that the fuse link 1152 might have beenblown, the ticket 700 is advanced by the stepper motor 1058 one step or0.002 inches. The support microcontroller 1102 again measures thevoltage on the link monitor line 1164 and if the voltage issignificantly below 5 volts, the stigmatization process is initiatedagain. After five such steps without a significant drop in the voltageon the link monitor line 1164, it is assumed that the fuse link 1152 hasbeen successfully blown. At this point, the stigmatization process hasbeen completed and the high voltage power supply 1154 is inhibited by asignal on line 1156. One advantage of using an electronic fuse junctionhaving dimensions larger than the excitation plate 1134 and the sensorplate 1132M, is that it is possible to test the fuse link 1152 over anumber of steps to ensure that it has been opened.

The following is the preferred criteria for using the circuit such asthe circuit 1096 in the electronic validation machine 1000 to stigmatizelottery tickets. Losing tickets can be stigmatized although there is noapparent advantage to doing so. Conversely, it is not apparent thatthere is any particular disadvantage to stigmatizing a losing ticket.Therefore, losing tickets will be stigmatized. Winning tickets should bestigmatized. In the event of a barcode misread, the ticket preferablyshould not be stigmatized. The electronic validation machine 1000 shouldback the ticket out and request a rescan. The ticket may have beeninserted backward or upside down.

With respect to improperly played tickets, the general conclusion is tostigmatize all of them. Regarding counterfeit tickets and tickets thathave been tampered with, as detected by measuring the electricalproperties of the fuse link 1152 as described above, the ticket shouldnot be stigmatized. Rather the ticket should be retained by the lotteryagent and submitted for analysis.

D. Document Thickness Measurement

FIG. 107 illustrates another significant feature of the electronicvalidation machine 1000 which is the capability of measuring thethickness t of the substrate of a lottery ticket and similar typedocuments. This feature will be described in connection with the lotteryticket 700.

As discussed above, the primary electrical signature value that theelectronic validation machine 1000 utilizes is capacitance. Factorsinfluencing capacitance listed below:

C=K∈ ₀(A/t)

where:

C=Capacitance (in Farads)

K=Dielectric Constant

A=Area of Electrodes (inches²)

t=Electrode Spacing—dielectric thickness (inches)

∈₀=Constant—0.225 Farad/inch

When there are no conductive or semiconductive ink films located beneaththe sensor head 1036 shown in FIG. 100, the electrical waves produced bythe excitation bus bar 576 will penetrate through the substrate of thedocument such as ticket 700 and appear to reflect off of the pressureroller 1056 as indicated by a pair of arrows 1168 and 1170. Also, itshould be noted that it is desirable that the pressure roller beinsulated from ground to achieve this reflection effect. The reflectedsignal is absorbed by the channel sense capacitors 1132A-1132M and canbe processed as an electrical signature for the ticket's paper stock byelectronic validation machine 1000 as described above. Thus, electronicvalidation machine 1000 can evaluate the thickness (t) of a ticket'spaper substrate as well as the composition (K) of the substrate. For thefrequency range of the electrical illuminating signal used in electronicvalidation machine 1000 as indicated above, the dielectric constant oftypical paper stock (K_(p)) will range between:

K _(p):3.29≦K _(p)<4.8

As a practical matter this relative small dielectric range (1.51) forticket paper substrates in itself has minimal impact on ticket securitydetermination in this particular example. However, evaluation of thethickness t of the substrate can be very important to lottery ticketsecurity. The electronic validation machine 1000 will normally read alottery ticket's barcode to determine if the ticket 700 has winningindicia printed under its scratch-off latex. On a traditionalscratch-off lottery ticket, the barcode is almost always printed on theback of the ticket. Therefore, it is possible to defraud the lottery bysecuring an unplayed ticket behind a properly played ticket and feedingboth ticket through the electronic validation machine 1000 assuming thatthe electronic validation machine 1000 will scan the latex of the frontticket and the barcode on the back of the ticket.

However, by measuring the thickness t of the substrate 702 of thelottery ticket 700 at the trailing edge of the ticket where noconductive materials are located, it is possible to determine ifadditional material such as another ticket has been added to the ticketundergoing validation. As illustrated in FIG. 107, when scanningnon-latex areas of a scratch-off the ticket 700, the paper substrate 702functions as a large part of the coupling capacitor's dielectric.Because both the thickness (t) and dielectric constant (K) of acapacitor's dielectric affect the coupling capacitance and because thedielectric constant for a ticket's paper substrate (K_(p)) does not varyover a significant range and because the capacitance C is divided by thethickness (t) of the dielectric of the coupling capacitor increasing theinfluence of the dielectric's thickness (t) on the sensed couplingcapacitance, the electronic validation machine 1000 can easily detect anadditional ticket between the front ticket 700 and the pressure roller1056. For example, the coupling capacitance sensed by the electronicvalidation machine 1000 for a single 10 point (0.01 inch) ticketsubstrate would be approximately:

C=K∈ ₀(A/t)

C=4∈₀(0.1/0.01)

C=40∈₀

As a result, the coupling capacitance sensed by the electronicvalidation machine 1000 for a ticket having a substrate double thethickness of the substrate 702 of the lottery ticket 700 would beone-half of the value measured for a single ticket:

C=4∈₀(0.01/(2×0.01))

C=20∈₀

Thus, the change in the sensed capacitance C and therefore a differencein the thickness (t) is readily detectable by the electronic validationmachine 1000.

The composition of the pressure roller 1056 is important in making itelectrically reflective. For example, if the pressure roller 1056 ismade out of a typical rubber compound with carbon particles embedded inthe rubber, the direct current (dc) resistivity of the pressure roller(ρ_(roller)) has a very high value:

ρ_(roller)>2 MΩ/cm

This is not surprising because this roller is primarily made of a rubberbinder surrounding numerous carbon particles. Rubber is a commonly usedinsulator and has a very high dc resistivity:

ρ_(rubber):8×10¹²≦ρ_(rubber)≦2×10¹⁵ Ω/cm

Carbon, on the other hand has a relatively low resistivity (ρ_(carbon)):

ρ_(carbon)≈35 KΩ/cm

This composite roller has a very high dc resistivity because itsnumerous carbon particles are encapsulated in the high resistivityrubber binder. Therefore, there is no low resistance dc path from onecarbon particle to another.

However, this arrangement of carbon particles encapsulated by very thinfilms of rubber (micron level) causes the composite roller to exhibit avery high dielectric constant, K_(roller)>>300. Apparently due to theclose proximity of conductive carbon particles insulated by thin filmsof rubber which create a 3-dimensional network comprised of a largenumber of capacitors. Thus, the network consists of numerous microscopiccapacitors in a complex arrangement of series and parallel ResistanceCapacitance (RC) circuits.

For the excitation frequency range used in the electronic validationmachine 1000, the dielectric constant of rubber compounds, excludingpolysulfide rubber (K=2260), ranges from a low of 2.38 (Butyl rubber) toa high of 6.60 (Neoprene rubber). Assuming a rubber dielectric of K=6.60(for neoprene,) the capacitance between the carbon particles would notbe large unless the thickness of the dielectric is very small.Preferably, the best way to obtain small dielectric spacing is with highcarbon loading, that is the percentage of carbon particles relative torubber binder contained in the composite roller material. By increasingthe percentage of carbon particles relative to rubber binder the spacingbetween the individual carbon particles will be reduced. Thus, it isbelieved that the very small spacing between the conductive carbonparticles causes the pressure roller to effectively exhibit an extremelyhigh dielectric constant. As a result, the preferred composition of thepressure roller 1056 is a nonconductive elastomeric material, such asrubber, encapsulating a large number of conductive particles, such ascarbon.

XIII. Other Applications of the Invention

The present invention is not limited to validating or determining theauthenticity and integrity of probability game, pull-tab or other typesof lottery tickets, but is applicable in many circumstances in which barcode readers and magnetic stripes are used. For example a document suchas a stock certificate could be printed with electronic circuits similarto the resistors 82-96 printed on the lottery ticket 50 where theelectrical signatures of the circuits represent verification data suchas a serial number. Human readable document data such as the serialnumber would also be printed on the stock certificate. The electronicverification machine 108 or 500 would then electrically couple with thecircuit elements as described above to generate a verification signalrepresenting the electrical signatures and hence the verification data.Authentication of the certificate is then accomplished by the processorboard 220 or terminal 532 which relates or compares the verificationsignal to a data signal representing the document data. The data signalcan be generated by an optical character reader or a user interface suchas the keyboard 178. In this manner the electronic document machine canverify that the serial number printed on the certificate is the correctone for the certificate and thus authenticate the document.

It will then be appreciated that the present invention will have utilityin a variety of areas including coupon redemption, inventory security,airport tracking systems, magnetic stripes, currency security, compactdisk security, drivers license and passport security. Coupon fraud is aserious problem for the retail industry. Current estimates of money lostto coupon fraud range in the hundreds of millions of dollars. Moreover,with the advent and growth of desk-top publishing andcolor-photocopiers, the opportunities for coupon fraud as well as othertypes of document fraud will increase. The present invention can be usedto stem the growth of coupon fraud. Providing coupons with an electricalsignature by printing at least a portion of an electric circuit on thecoupons, according to the invention, would provide the ability to verifythe authenticity of the coupons submitted for payment. Further, byutilizing the stigmatizing technique described above it will be possibleto prevent coupons from being redeemed more than once. As to inventorysecurity, the circuits according to the present invention can be printeddirectly on an inventory ticket, price tag or manufacturer's tag thussupplanting the use of metal strips and coils. Airline ticket fraud,which may also cost hundreds of millions of dollars annually, presentanother application for the present invention. Circuits according to thepresent invention could be used to ensure the authenticity and integrityof airline tickets. In addition, the present invention could be used totrack the luggage associated with airline travel. The present inventioncan also be used as an effective alternative to magnetic stripes.Magnetic stripes contain identification numbers, for example, creditcard numbers, that are programmed at manufacture. The stripes are proneto failure and are subject to fraud because they are easily copied ormodified. To overcome these shortcomings, circuits according to thepresent invention could be printed on a substrate and encoded withspecific customer information. Thus the present invention can be used toimprove the security of credit cards, automatic teller machine (“ATM”)cards, and any other tracking card which uses magnetic stripes as asecurity measure. The present invention can also be used to mitigate thelosses resulting from currency fraud which includes, for example,counterfeit currency, and check forgery. Counterfeiting of thesedocuments could be reduced if the documents were provided with anelectrical signature or conductive fibers as described above. Theinvention could be used in the same manner to improve the security ofdrivers licenses and passports. The invention could also be used toprovide inventory control of compact disks which, because of their smallsize, are subject to theft. Circuits according to the present invention,which included RF devices, could be used to track the compact disks andto prevent their clandestine removal.

Although the present invention has been described with reference topreferred embodiments, it will be understood that various changes andmodifications will be suggested to one skilled in the art and it isintended that the invention encompass such changes and modifications asfall within the scope of the appended claims.

We claim:
 1. A verification machine for use with lottery tickets havingplayer removable play spots covering play indicia, comprising: ahousing; a transport mechanism for moving the lottery tickets throughsaid housing; a source of electromagnetic energy located within saidhousing; and a detector circuit including an array of photo-detectorsresponsive to said electromagnetic energy and responsive to the movementof the lottery tickets through said housing to generate a signalindicating which of the player removable spots have been removed fromthe lottery tickets.
 2. The machine of claim 1 wherein said transportmechanism moves the play spots into registry with said array ofphoto-detectors.
 3. The machine of claim 2 further including astigmatizing circuit including a DC voltage supply for stigmatizing thelottery tickets.
 4. The machine of claim 3 wherein the lottery ticketsincludes a fuse element and wherein said circuit for stigmatizing thelottery tickets include: first and second pads disposed to the lotteryticket aligned with the fuse element; a control circuit including amicrocontroller adapted to control said stigmatizing circuit; a switch,operatively connected to said control circuit, and connected betweensaid voltage supply and said first pad for selectively applying a DCvoltage from said power voltage supply to the fuse element via saidfirst pad; and a voltage discharge circuit connected to said second pad.5. The circuit of claim 4 wherein said control circuit causes saidtransport mechanism to align said the fuse element with said first andsecond pads.
 6. The circuit of claim 5 wherein said control circuitadditionally includes means for determining the status of the fuseelement after said DC voltage has been applied to the fuse element. 7.The circuit of claim 5 wherein said control circuit additionallyincludes means for measuring the value of said DC voltage from saidvoltage supply.
 8. An electronic verification machine for a lotterytickets having a plurality of play indicia and a plurality of playerremovable play spots, each of the player removable play spots coveringat least one of the play indicia, and ticket data including redemptioninformation; comprising; a detector including an array ofelectromagnetic sensors adapted to generate a removed spot signalidentifying which of said player removable play spots have been removedfrom the lottery tickets; and a reader configured to read at least aportion of said the ticket data.
 9. The machine of claim 8 wherein thelottery tickets include at least one electrical circuit element locatedin registry with the play spots and said detector detects the presenceor absence of said circuit elements on said the lottery ticket togenerate said removed play spot signal.
 10. The machine of claim 8wherein said array of electromagnetic sensors includes an array ofphoto-detectors responsive to an electromagnetic energy source and iseffective to generate said removed play spot signal.
 11. The machine ofclaim 8 additionally including an indicator display adapted to displayinformation relating to the status of said machine.
 12. The machine ofclaim 8 additionally including a printer responsive to said readeradapted to print information relating to the lottery ticket.
 13. Alottery ticket verification machine for validating probability lotterytickets having predetermined play rules, a plurality of player removableplay spots covering play indicia, and validation data printed on saidticket, and electromagnetic responsive material printed in registry withsaid play spots on said lottery ticket; comprising: a digital processor,a data reader for reading the validation data, said data reader beingoperatively connected to said digital processor, an electromagneticsensor operatively connected to said digital processor and configured todetect said electromagnetic responsive material on the ticket; a ticketinterface and transport mechanism operatively connected to said digitalprocessor and adapted to receive said lottery tickets and to positionthe validation data and the play spots with respect to said data readerand said electromagnetic sensor respectively; and wherein said digitalprocessor is additionally effective to generate from saidelectromagnetic sensor a play spot signal indicating which of said playspots have been removed from said the lottery ticket.
 14. The machine ofclaim 13 wherein said electromagnetic responsive material is printed onthe lottery tickets in the form of a circuit element and wherein saidlay spot signal represents an electrical signature of the circuitelement.
 15. The machine of claim 14 wherein said play spot signalrepresents an electrical signature of said circuit element.
 16. Themachine of claim 13 wherein said electromagnetic sensor is an opticaldetector.
 17. The machine of claim 16 wherein said play spot signalrepresents an optical signature of the play spots.
 18. The machine ofclaim 16 wherein said optical detector is a photo detector and isconfigured to detect and classify a frequency of light emitted by saidthe play spots.
 19. The machine of claim 18 wherein said memory storessaid the validation data in a form representing an electromagneticsignature of said the electromagnetic responsive material.
 20. Themachine of claim 13 additionally including a stigmatization circuitoperatively connected to said digital processor and configured tostigmatize the lottery ticket after said digital processor has generatedsaid play spot signal.
 21. The system of claim 20 wherein saidstigmatization circuit includes a source of electromagnetic energy forapplying sufficient electromagnetic energy to a surface of the lotteryticket to alter a color of said the lottery ticket.
 22. The system ofclaim 20 wherein the lottery ticket additionally includes a fuse elementand said stigmatization circuit includes a voltage source adapted toapply sufficient power to said the ticket to break said the fuseelement.
 23. The system of claim 19 wherein the lottery ticket includesa temperature sensitive material and said stigmatization means includesan electromagnetic energy source adapted to apply sufficientelectromagnetic energy to said temperature sensitive material to causesaid temperature sensitive material to change color.
 24. The system ofclaim 13 wherein said the lottery ticket includes a plurality of circuitelements printed on a surface of said the lottery ticket and saidmachine includes a power source operatively connected to said digitalprocessor effective to apply sufficient power to at least a portion ofsaid circuit elements to alter said the portion of said the electroniccircuit elements thereby storing information in said portion of saidcircuit elements.
 25. A lottery ticket verification machine for avalidating probability lottery tickets having a player removablematerial located in predetermined locations on the ticket, comprising: adigital processor; a document channel; a sensor array operativelyconnected to said digital processor; a transport mechanism operativelyconnected to said digital processor effective to transport the lotteryticket through said document channel such that at least a portion of theplayer removable material is aligned with said sensor array; a memory;and a scanning circuit operatively connected to said digital processorand to said sensor array for generating in said memory a scanned bit mapof at least a portion of the player removable material.
 26. The machineof claim 25 wherein said memory additionally includes validation data.27. The machine of claim 26 wherein said validation data includes alocation of the player removable material.
 28. The machine of claim 26wherein said validation data includes the shape of the player removablematerial.
 29. The machine of claim 26 wherein said validation dataincludes an expected percentage of removal of the player removablematerial.
 30. The machine of claim 27 wherein said percentage representsa minimum percentage of the player removable material for a playedlottery ticket.
 31. The machine of claim 30 wherein said minimumpercentage is 30 percent.
 32. The machine of claim 27 wherein saidvalidation data is contained in said memory as a bit map.
 33. A lotteryticket verification machine for validating a probability lottery ticketshaving a plurality of player removable play spots covering play indicialocated in predetermined locations on the probability lottery ticket,and validation data printed on the probability lottery ticket; ahousing; a sensor array located in said housing; a document channelconfigured in said housing; a transport mechanism including a motorlocated in said housing that is effective to transport the probabilitylottery ticket through said document channel such that the playerremovable play spots are aligned with said sensor array; at least oneticket location detector; and a digital processor located in saidhousing and operatively connected to said sensor array, said transportmechanism and said ticket location detector effective to cause theplayer removable play spots to be scanned as the lottery ticket istransported by said transport mechanism past said sensor array.
 34. Themachine of claim 33 wherein the validation data is printed as a bar codeon the lottery tickets, and wherein the machine includes a bar codereader located in said housing operatively and connected to said digitalprocessor, and wherein said digital processor is effective to read thevalidation data when the bar code is transported by said transportmechanism past said bar code reader.
 35. The machine of claim 34 whereinsaid ticket location detector includes a plurality of edge detectors.36. The machine of claims 34 wherein a first of said edge detectorsprovides an indication to said digital processor of when one of thelottery tickets is in said document channel, a second edge detectorprovides an indication to said digital processor of the location one ofthe lottery tickets in said document channel, and a third of said edgedetectors provides an indication to said digital processor of when oneof the lottery tickets has exited said document channel.
 37. A lotteryticket verification machine for validating a probability lottery ticketshaving a player removable material located in predetermined locations onthe ticket and validation data printed on the probability lotteryticket, comprising; a housing; a sensor array located in said housing; adocument channel configured in said housing; a transport mechanismincluding a motor located in said housing that is effective to transportthe probability lottery ticket through said document channel such thatthe player removable material is aligned with said sensor array; atleast one ticket location detector; a digital processor located in saidhousing and operatively connected to said sensor array, said transportmechanism and said ticket location detector effective to cause theplayer removable material to be scanned as the probability lotteryticket is transported by said transport mechanism past said sensor arrayin order to generate a digital representation of the location of theplayer removable material on the probability lottery ticket.
 38. Themachine of claim 37 wherein the player removable material includesplayer removable play spots covering play indicia located inpredetermined locations on the lottery ticket and wherein said digitalrepresentation represents the play spots that have not been removed fromthe probability lottery ticket.
 39. A lottery ticket verificationmachine for use with a probability lottery tickets having predeterminedplay rules, and including validation data printed on said theprobability ticket in a bar code format, and a plurality of playerremovable play spots covering play indicia located in predeterminedlocations on the probability lottery ticket, comprising: a housing; adocument channel configured in said housing; a sensor array located insaid housing; a bar code reader located in said housing a transportmechanism including a stepper motor operatively connected to a pluralityof rollers located in said housing effective to transport said theprobability lottery ticket through said document channel past saidsensor array and said bar code reader; at least one ticket locationdetector; a memory operatively connected to said controller located insaid housing and containing data removed play spot data and furthercontaining at least a portion of the validation data; and a digitalprocessor operatively connected to said sensor array, said bar codereader, said ticket location detector, and said memory, wherein saiddigital processor is responsive to said ticket location detector tocause said transport mechanism to move the probability lottery ticketspast said sensor array; cause the said sensor array to scan theprobability lottery tickets to determine which play spots have beenremoved; input into said memory information relating to said removed theplay spots which have been removed into said memory; cause the saidtransport mechanism to move the probability lottery tickets past saidbar code reader; cause the said bar code reader to place at least aportion of the validation data in said memory; and to cause saidtransport mechanism to exit the lottery probability lottery tickets fromsaid document channel.
 40. The machine of claim 39 wherein said sensorarray includes a plurality of sensor plates.
 41. The machine of claim 29wherein said sensor array includes at least one optical detector. 42.The machine of claim 41 wherein said optical detector is a photodetectorand is configured to detect and classify a frequency of light emitted bythe player removable play spots.
 43. The machine of claim 39 whereinsaid housing additionally includes a stigmatization circuit thatincludes including a source of electromagnetic power and which isoperatively connected to said digital processor for stigmatizing theprobability lottery ticket prior to said transport mechanism exitingsaid the probability lottery tickets from said document channel.
 44. Themachine of claim 43 wherein said source of electromagnetic power appliessufficient electromagnetic power to the probability lottery tickets tochange a color of least a portion of the probability lottery tickets.45. A lottery ticket validation machine for use with a probabilitylottery ticket having predetermined play rules and including a pluralityof player removable play spots covering play indicia located inpredetermined locations on the ticket and validation data printed on theticket, comprising: a digital processor, a document channel; aphoto-detector array operatively connected to said digital processor; atransport mechanism operatively connected to said digital processoreffective to transport the probability lottery ticket through saiddocument channel such that at least a portion of the play spots aresubstantially aligned with said photo-detector array; a scanning circuitoperatively connected to said photo-detector array for generating afirst signal indicating which of the play spots have been removed fromthe probability lottery ticket; a data reader operatively connected tosaid digital processor for reading the validation data and generating asecond signal representing at least a portion of said validation data; amemory operatively connected to said digital processor; and wherein saiddigital processor is effective to store said first and second signals insaid memory.
 46. A lottery ticket validation machine for use withprobability lottery tickets having predetermined play rules, andincluding a plurality of player removable play spots covering playindicia located in predetermined locations on the tickets, andvalidation data printed on the tickets, comprising: a digital processor,a document channel; a sensor array operatively connected to said digitalprocessor; transport mechanism including a stepper motor and a pluralityof ticket detectors operatively connected to said digital processoreffective to transport the probability lottery tickets through saiddocument channel such that at least a portion of the play spots aresubstantially aligned with said sensor array; a scanning circuitoperatively connected to said sensor array for generating a first signalindicating which of the play spots have been removed from theprobability lottery tickets; a data reader including a bar code readeroperatively connected to said digital processor for reading thevalidation data and generating a second signal representing at least aportion of said the validation data; a memory operatively connected tosaid digital processor; and wherein said digital processor is effectiveto store said first and second signals in said memory.
 47. The machineof claim 46 additionally including a stigmatization circuit including asource of electromagnetic power operatively connected to said digitalprocessor effective to apply sufficient electromagnetic power to theprobability lottery tickets after the probability lottery tickets havebeen scanned by said scanning circuit to change a color of at least aportion of the probability lottery ticket.
 48. A lottery ticketvalidation machine for use with probability lottery tickets havingpredetermined play rules and including a plurality of player removableplay spots covering play indicia located in predetermined locations onthe tickets and validation data printed on the probability lotterytickets, comprising: a housing; a digital processor located in saidhousing, a document channel located in said housing; a sensor arraylocated in said housing and operatively connected to said digitalprocessor; a transport mechanism located in said housing, including astepper motor, a plurality of rollers operatively associated with saidstepper motor and adapted to engage the probability lottery tickets, anda plurality of ticket detectors operatively connected to said digitalprocessor effective to detect the insertion and position of theprobability lottery tickets in said document channel, and said transportmechanism being effective to transport the probability lottery ticketsthrough said document channel such that at least a portion of the playspots are substantially aligned with said sensor array; a scanningcircuit located in said housing operatively connected to said sensorarray and said digital processor for generating a first signalindicating which of the play spots have been removed from theprobability lottery tickets; a data reader, including a bar code reader,located in said housing including a bar code reader and operativelyconnected to said digital processor for reading the validation data andgenerating a second signal representing at least a portion of thevalidation data; and a memory operatively adapted to receive said firstand second signals from said digital processor.
 49. The machine of claim48 wherein a first of said ticket detectors indicates to said digitalprocessor that one of the probability lottery tickets is in saiddocument channel.
 50. The machine of claim 49 wherein said digitalprocessor responds to said first ticket detector to cause said motor torotate a first of said rollers thereby moving the probability lotteryticket past said sensor array.
 51. The machine of claim 50 wherein asecond of said ticket detectors indicates the location of theprobability lottery ticket to initiate scanning of the probabilitylottery ticket by said scanning circuit.
 52. The machine of claim 51wherein a third of said ticket detectors indicates that the probabilitylottery ticket has exited said document channel.
 53. The machine ofclaim 49 wherein said sensor array includes a plurality of sensorplates.
 54. The machine of claim 49 wherein said sensor array includesat least one optical detector.
 55. The machine of claim 54 wherein saidoptical detector is a photodetector and is configured to detect andclassify a frequency of light emitted by the player removable playspots.
 56. A verification machine for a lottery ticket having playerremovable material covering cover play indicia located in predeterminedlocations on the ticket, comprising: a housing; a digital processorlocated in said housing, a document channel configured in said housing;a sensor located in said housing and operatively connected to saidcontrollerdigital processor; a data reader operatively connected to saiddigital processor and adapted to read the bar code; a transportmechanism located in said housing and operatively connected to saiddigital processor, said transport mechanism including a plurality ofticket sensors and a motor effective to transport the probabilitylottery ticket through said document channel such that at least aportion of the play spots is substantially aligned with said sensor; ascanning circuit operatively connected to said sensor and to saiddigital processor for scanning at least a portion of the lottery ticketfor the player removable material; a memory operatively connected tosaid digital processor and containing a first set of data representingpredetermined locations of the player removable material on the lotteryticket; and wherein said digital processor is effective to transmit tosaid memory a second set of data from said scanning circuit representingthe actual locations of said player removable material on the lotteryticket to said memory for comparison with said first set of data. 57.The machine of claim 56 wherein said first and second sets of datarepresent the shape of the player removable material.
 58. The machine ofclaim 57 wherein said first and second sets of data are contained insaid memory as a bit map.
 59. The machine of claim 56 wherein saidsensor includes an array of sensor plates.
 60. The machine of claim 56wherein said sensor includes an array of photo detectors.